megamush, I did know where the link to the whole soundtrack was, but... uh... the link escapes me at the moment.
I've narrowed it down to my top 15 in alphabetical order. Of those, the top three for me are 1. Mario Circuit (congratulations!), 2. Yoshi's Island, and 3. Space Armada (gotta have Star Fox on there).
Bramble Blast - Donkey Kong Country 2 (nothing compared to the original, but still a great remix)
Castle/Boss Fortress - Super Mario World/SMB3 (I associate this with the Koopalings. The song's slow, but that just adds to the creepiness. Very well done)
Corneria - Star Fox (they put in Corneria! YES!!! One of the best songs in the entire Star Fox series. Unfortunately, the Space Armada remix outshines it)
Humoresque of a Little Dog - Mother (Let's not beat around the bush, I know this as EarthBound's Drugstore. Heck yeah, amazing. Snowman is in 16th, off the list. I was debating whether to have Snowman or this, but come on, the Drugstore!)
Jungle Level Ver.2 - Donkey Kong Country (aka Jungle Hijinx. Hearing this again reminded me how much DKC's soundtrack rocked. Going from the MP3, my favorite part is 1:40-2:05, that's when it breaks from the melody and goes mysterious)
Lip's Theme - Panel de Pon (I really know this to be the same thing as Yoshi's Theme from Tetris Attack (which was one of my favorite themes from that game), so naturally it has to be on this list)
Main Theme - Star Fox (til the day I die, this will always be the true Star Fox theme for me. I'm still amazed that the SNES version really doesn't sound any different from this, though)
Mario Circuit - Super Mario Kart (frickin' legendary, I declare this one of the best videogame remixes of all time. Favorite song in Brawl. Also gotta love the Lakitu 3-2-1 sounds during the bridge)
Mute City - F-Zero (it's incredibly difficult to impress me with Mute City because I always hold the SNES version as the best, even with the numerous remixes over the years. But I think at long last, the Brawl version challenges that position. The thing that's been holding up the other versions is the opening part before it gets to the melody. That's my favorite part and no version had done justice to it (except Sounds of Mute City in F-Zero GX, but then they screwed up the rest of the song by not being daring enough and doing a strange duet), until now. Awesome)
Onett - Smash Bros Melee (I hate the little changes made in the Brawl version, but this is still the best Melee track and the best EarthBound song I've ever heard. Yes, even better than the Mother Japanese soundtrack, though barely)
Space Armada - Star Fox (excellent remix. Love how the notes are drawn out. Epic song)
Space Battleground - Star Fox Assault (this seriously made me reconsider my "not gonna touch it with a 10-foot-pole" grudge against Assault, because this song rocks. Sure, it's incredibly short, but I love that melody)
Underground Theme - Super Mario Bros. (actually, it might be one of my favorites simply because of the awesome remix in Super Mario RPG as the Axem Rangers are running away. The sweet instruments used here totally remind me of that)
White Land - F-Zero (remix of White Land! I usually don't think much of F-Zero music beyond Mute City or Big Blue because their music isn't as distinctive or memorable, but occasionally they really stand out, like this one does)
Yoshi's Island (this is the best tribute a Yoshi fan could hope for. Frickin' love the harmonica. I swear there's too many "Yoshi's Island"s out there, so this is the jazzy remix of Make Eggs Throw Eggs from SMW2 with the harmonica)