I'm going to have to go with orange box on this, and I haven't even played that. Portal is brilliant, Team Fortress 2 is the first Online Multiplayer FPS that I've EVER been interested in, and half life 2 has a really decent storyline from what I can see so far.
I was never huge on the Original Super Mario Bros or the Lost Levels, though 2 was okay and 3 was brilliant, but even with that, I can't really get behind the idea that Mario Allstars did that much.
It might just be timing though. Orange Box was how most people were INTRODUCED to Portal, Team Fortress 2 and Half Life 2, which I believe were all released seperately later. With Mario Allstars, it was a repackaging; a good deal, but nothing groundbreaking, except perhaps savepoints.
EDIT: Oooh, Onyxmeth brings up a good point. Adding Super Mario World to that mix increases the value drastically. It's pretty close when you factor in relative time periods, but I'd still put Orange box ahead, mostly due to having such a diverse mix of game styles that all use roughly the same game mechanics