chevkoch: Anyone got more recommendations out of what they've seen?
There are too many to list, so I'll pick my favourite from every ~12 hours of the marathon.
Full disclosure, I have some very thick nostalgia glasses, a strong interest in RNG manipulation and I'm not a fan of races.
Batman: Arkham Asylum - I didn't have a huge interest in the games run for the first 12 hours, so this is a bit of a default win.
Contra - great co-op run, pretty much as close to a Contra WR as you'll get in a marathon.
Metal Gear Solid - I didn't even know there was a (buggy as all hell) PC version of this game.
Castlevania: Symphony of the Night - zero bosses is a very entertaining run.
Fire Emblem: The Sacred Stones - this is likely my nostalgia/RNG bias, but it has loads of both for me (RE 7 gets an honourable mention)
Holy Diver - the game itself is so absurd that it's almost an auto win. (Kid Icarus gets an honourable mention)
Battletoads - stick around after for the blindfolded turbo tunnel! (Dragon Warrior gets an honourable mention)
Superman 64 - this has more glitches than game. (everything else in the awful block gets an honourable mention)
Umihara Kawase - very interesting grapple game and some good commentary too. (Star Fox 2 gets an honourable mention)
Densha de D: Lightning Stage - this game is just absurd and the runners even went through the trouble to translate it for you! (halfcoordinated's runs get an honourable mention)
Mike Tyson's Punch-Out!! + Super Punch-Out!! - playing two games with the same inputs, nuff said.
Kirby: Canvas Curse - very unique control scheme, made for an interesting run.
For the runs that are comming up, it'll probably be a toss up between Warcraft III, Baldur's Gate 2, or Final Fantasy IV.
Edit: Can't decide between Baldur's Gate 2 and Final Fantasy IV... Go with BG2 if you don't have much time and FFIV when you have a couple hrs.