How will you get access to games? Do you program them or know programmers? I do game music. I'd host the games, hotlinking isn't ideal for many reasons.
When it comes to Arcade games you really can't beat the classics. I'm talking Pacman, Tetris, Space Invaders, Centipede, etc.
Sega / DOS / Snes originals which have been upgraded to HD are also big right now.