Summary: What a lazy cashgrab. You can literally play all these games on Newgrounds for free. All Mr. McMillen did was slap achievements onto them. That's it. They're not even good games. Why would you pay money for this garbage? Stop supporting lazy indie developers!
Summary: Even though you can play these games online for free, the collection offers extra artwork, videos, and interviews which are pretty great to see and hear. Besides, it's cheap. Anyway, the game themselves offer hours of challenge and entertainment.
Summary: Aside from all the blind "Indi3 L0v3" floating around everything Edmund McMillen does (and eats) I'm pretty positive The Basement Collection can be described in few words, and I allow myself to borrow said few words from FloppiZock's Metacritic review: "A little collection of cute games".
Summary: Some of the games (Aether in particular, perhaps Triachnid as well) aren't quite games so much as they are interactive art of a kind. But 3 chapters of the original Meat Boy as well as Time Fkcu Spewer make this worth the paltry $2.99.
Summary: This game completes nerds. Great stuff, very thorough and much added. Lots of hidden gems. Spewer is awesome... and I think Portal 2 should pay love to it for the variants of liquid goo that serve particular purposes. Aether is one of my favorite games and I'm glad it's back with some updated goods.
Summary: Half of the things in the collection really aren't worth the money (unless you love Ed as much as I do), especially since they barely changed from their free counterparts, but Time F. is pretty much worth it on its own. Double the content and custom levels? Heck yes. Spewer is pretty neat as well.