I'm mediocre lol. I don't read sheet music much, the only chords I know is C and F or something. I don't use my pinky often in songs too, my fingering is bad. I usually use Synthesia videos to learn anime/video game songs.
I currently have Dear You, Wind Scene, Dango Daikazoku, and Twilight Techno under learning right now. I might drop Wind Scene and maybe even Dear You though. They've been incomplete for some time now, and I'm certain I have no intention to try to keep learning Wind Scene. Maybe Dear You though, just to get some girls. And because it's pretty easy. My main focus is Twilight Techno, because it's such an awesome song, and it's a way higher difficulty than the stuff I've been looking at up to this point.
I like the piano quite a bit, with cello being a distant second. I play a bit of classical music, but my sightreading is weak so it takes me a while to learn pieces. I'm working on Bach's Aria from BWV 988 at the moment. My favorite composers for piano is probably Chopin. J.S. Bach's music is great as well. Most of my repertoire comes from Chopin, I know: his preludes op. 28, no. 4, 7, and 20; his sonata no. 2 movement 3, or the funeral march; and his waltz no. 19 op. posth. I also know the first movement from Beethoven's Piano Sonata no. 14 (moonlight). I can also play the first movement of Mozart sonata k. 545, and J.S. Bach's Prelude in C Major (from the WTC book 1).
I'm probably a mediocre level 5 player (according to ABRSM)... I think my rubato and dynamics are generally good, but yeah, my sightreading is bad and I've never studied chords, scales etc. I'm fine with not studying them though, as I only play to enjoy myself and think they would be boring. And I don't do improv, etc, or anything which completely necessitates that I learn them.
I did try learning classical on electrical guitar, also. It didn't work out well for me. I think that the skill requirement for most pieces is much, much higher on guitar than on piano - well, naturally it would be, as the pieces were often composed for piano. I would definitely recommend either a classical guitar, or an actual 'classical' instrument, I.e. piano, violin, cello, etc.
That youtube video is pretty crazy for an amateur recording. Check these ones out as well:
I play it, (:
Although I haven't continued with the grades nor have I taken classes for a while, I think I am pretty good at playing.
I can easily learn a grade 10 song. I usually print out songs I like and play them / learn them.