Look, I don't own a PS3 but I plan on getting one. & one of the games I plan on buying is Metal Gear Solid. My problem is that on the Xbox 360, a system I own, they have an HD Collection that has a few of the games while on the PS3, they have the Legacy Collection, which has pretty much every Metal Gear Solid game from 1987-2012. So which one do I buy? The HD collection now so I can play a few games or wait til I get a PS3 & buy the Legacy collection where I can play a number of games?

Just wait and get the Legacy collection.

Might as well wait. Legacy Collection gives you the HD versions of 2 3 and Peace Walker.

More is better than less.

Wait till you get the PS3 then buy the Legacy Collection. I assume you haven't played a Metal Gear game before, so story wise you could only play two out of the three games in the HD collection (you could play MGS2, but its better if you have played MGS1). Also MGS1 and MGS4 are big games in the series and are not in the HD collection, so you are better off getting those as well.