"I Gotta Believe!" that it's time to acknowledge the unsung heroes of our time.
There's no need to guess who, because everyone reading already knows that I am talking about Parappa The Rapper™ freestylers. Yes, I have diligently combed through the deep, dark trenches of the internet to uncover these rhythmic wizards, and now I present to YOU (yes, YOU!) the historic footage! Before I begin... I should mention that THIS PLAYLIST contains one song per player, barring the last surprise video featured at the end. For multiple players it was a difficult decision as to which freestyle to feature. Ultimately, I chose using significant factors such as: view count, video author's preference, a noteworthy display of skill, etc. To get the most out of this thread, I suggest following the topic along as you watch through the playlist. Read the player's entry, and then watch their respective video. Each player has been separated into sections to make this easier.

(Provided is a short message about each player and the specific performance I have chosen)
1. Raisuke Fukaga - Oct. 6, 2006
The OG. Before there was light, there was Raisuke Fukaga's Parappa™ videos. With 1.8 million views, it sits as the most-viewed video on this playlist, and the only video where the player is not in "COOL". His videos have since been unlisted, and were tough to track down. Considering it's the first freestyler, it seemed appropriate to choose Chop Chop's chopping grounds as the setting-stage. As far as Parappa freestyles go there are more tenacious, complex examples available these days, but Fukaga's sense of Rhythm is undeniable.
2. Zashxq - June 6, 2007
After all these years, few have ever come close to the skill or notoriety of Zashxq. Carrying a recognizable style and technique, Zashxq's videos remain for many the definitive example of high-level play in PTR2™. His technique is simple, yet effective. Utilizing an always-slightly-shifting algorithm, Zashxq holds the right direction to hang on specific lyrics as he makes the contents of one line stretch over several. Boasting an understanding of vocal sample length, Zashxq frequently purposely places the longer words and pronunciations for the spaces needed in his rhythmic structures. His Food Court™ performance is his most viewed, and keen listeners will realize that he actually matches the master's lines with their respective bgm! The comments also leaves one reason to be excited:

We're waiting!
3. CrackCrackMaster - April 4, 2009
Definitely one of the most niche additions to this list, but one that I believe deserves recognition. I believe that CrackCrackMaster was ahead of their time. In the small snippet of footage available, the viewer can hear the Master express mastery of timing with the right direction during each series of double-taps. There is also increased emphasis on sentence-branching "Put the cake in the Cr-Crack, Crack Crack! All we gotta do is Cr-Crack, Crack Crack!". Master creates a flow that follows the bgm while remaining lyrically transformative, and combines D-Pad tech (both LEFT and RIGHT!) with "Sea Food Cake" to create a makeshift chorus! The biggest tragedy is that the song isn't complete...
4. ひでやん - Jan 10, 2010
One of two players from Japan featured on this list. The true beauty of this freestyle is the ability of the rapper to maintain a flow and direction with the skimpy offerings of the stage's soundboard. The algorithms remain similar enough to create a steady flow, but mutate just enough to avoid becoming too repetitive for the song's duration. A noteworthy feat considering the constraints of the level-design.
5. SunFireHyena (Formerly DaParappa) - April 15, 2011
Despite using savestates and a different bgm then what's found in the game, I still believe this freestyle deserves to be among "The Great Ones™". This freestyle by DaParappa is possibly the most popular Parappa freestyle of all time, and remains one of the best examples of sentence-branching. Honestly, I feel this performance pretty well killed Fleaswallow Freestyling... with various brand new lines that utilize almost every voice sample available, and a flow that only occasionally fails to give individual words their proper time to breathe. Freestyles made from this stage will likely struggle to simultaneously be lyrically transformative from the game's source lines AND avoid treading SunFireHyena's rhythmically beaten path. As a side note, SunFire has been an active member of the PTR community on and off for ages and even has his own fan-game-projects!
6. Poetdaina - October 30, 2013
The first entry featuring Gameplay of everyone's favorite jamming lamb is also the second Japanese player on the list. Another niche addition to the list, Poetdaina's showdown with Level 4 Rammy stands out to me thanks to the player's ability to play off the pre-programmed inputs of the AI while still creating a unique flow. From my experience, players typically avoid "R" due to the relatively excessive length of the guitar sample, but Poetdaina integrates it almost seamlessly with only the occasional slip-up. Considering how well each rift flows together, showing great understanding of each sample length and pitch, it's a shame that point scaling wasn't handled slightly better. This fight could've rode out even longer!
7. Tamatou (BLBridged/BLB Show/Sirtaki Master) - November 29, 2015
Years ago Tamatou and I were among those that were trying to break down the scoring engine for UJL, and boy was it fun! While I had reached 243 points in one line on video w/o fever, it was he that presented the first footage of 246. There was no way I could make this list and not feature his Stage 3 freestyle. It's rare to see a player able to make effective use of the effectors, and he manages to do so with Fever mode, to boot! Catchy rifts fill the song's duration, with sparing, yet effective use of the directions cleverly breaking up what could otherwise become a monotonous set of algorithms. As far as I am concerned, the "Wah Wah" will always belong to Tamatou in UJL! As a side note, he's created various types of interesting PTR content over the years including this retrospective.
8. Sonic Hedgehog - February 10, 2016
For all that Sonic's videos may lack in recording quality they more than make up for in gameplay quality. Typically fever is avoided, or is utilized as a small accessory to a freestyle. Sonic Hedgehog, however, made entire sets revolving around fever inputs. There's a nice, beatdown-thumping aggression to this performance. The shifts in tempo display the player's mastery over each of the "sample sets" in each fever input. Seamlessly, Sonic transfers from a rapid-multi-tap based algorithm commonly found in the use of fever Circle to perfectly-spaced triangle sets. These maneuvers are performed so naturally that they sound like fever isn't even utilized!
9. TruKuu (Gamersof Glory/DaBargainBin) - March 14, 2016
I feel a little narcissistic for putting myself on this list, but it is the will of the people (You know who you are). If I were to be on the list though, there's no doubt this would be the song to accompany my entry. Thanks to oddMLan, Masaya Matsuura caught wind of this freestyle, and I'm proud that he watched and enjoyed it.

The performance itself was a result of learning various algorithms, sentence branches, and improvisational skills. Thanks to individual sample study, a steady flow of "Mama, didn't you know? I'm gonna start a trick. Mama, didn't you know? Somebody hold me tight!" could sound like it was actually the original lyrics.
Thanks for a wonderful game Matsuura!
10. Posesix - Feb 10, 2017
Another contender for the most famous Parappa player of all time, Posesix was as great a freestyler as he was a modder. In the small amount of contact I had with him I learned that he had dissected each game's engine and broken down the scoring to a science. There are various livestreams displaying his gameplay, and I recommend checking them out. Seemingly out of nowhere he vanished, and while there are allegations as to how and why he left, I have yet to see anything concrete. All mods and mystery aside, February Freestyle is original, catchy, transformative and skillful. This is the best use of PTR2's lyric mechanics I've seen. The utilization of PTR2's ability to leave specific-button lyric sets combined with the right direction means that brilliant lines such as "You carry a single camera for all your single adventures!" are possible, but only if you're good enough to make it happen!
11. The Future - 2020 - Onwards
If you've read this far then thanks, and I hope you've enjoyed the provided freestyles. I will refrain from saying much as I want it to have time to speak for itself. Just know that there will be even more, and I believe that freestyles will only continue to develop and improve in these games.
I'm aware that there are several high-scoring players out there I did not place on this list, and that's because to me a high-score alone is not an important enough factor to warrant being a great freestyler. Scoring can be manipulated quite easily once someone learns the algorithms, but a great freestyle develops, has direction, and as I have mentioned several times, is lyrically transformative. The players I have highlighted understand the rules of the game, but also understand lyrically and audibly the components required to make a performance greater than the sum of its parts.
Do you know any other great freestylers for the PTR games that I didn't mention here? Link 'em here. Don't hesitate to share your thoughts about the thread/players mentioned, either!
an inspiring read... thanks trukuu!