One is my favorite album, so that. It's been a long time since I've really thought about a top 10 (or top whatever) of all time, but if I did one, most or all of my top 5 and more than half of my top 10 would have Mike Portnoy as drummer.
Off the top of my head, a lot of those would be: One, SDOIT, SFAM, The Whirlwind, The Great Adventure, SMPT:e...