Winnebagel

The Red/Blue type is called Anaglyph 3D and requires 3D glasses.

The kind that you see that is in like Magic Eye books and similar things is called Steroscopic 3D I believe, and it normally doesn't require glasses.

My personal favorite currently, for DVDs anyway, is called Field Sequential 3D. It does require you to wear special shutter type glasses you plug in, but I think it produces a very good effect.

I am a total nerd for 3D incidentally. I try to buy nearly every 3D movie I can find and games too, if I can find them.