Easy decision PS3. Sooo many great games, and PS4 won't be b/c and it will be ages before they get the cloud gaming working well enough to be able to play the prior gens' back catalogs that way. Also save yourself a bit of money by waiting to buy PS4 until at least the first price drop.

Which one?

I would go for PS3, but if you don't mind waiting for E3 you could hold off. I assume we shall see more Ps4 stuff and hopefully we would see Gaikai at work there.

Price, lack of time, too many PC games to play and lazyness/forgetfulness all kinds of reasons. Like not having a TV (for various reasons) so needing to use my PC monitor and monitors generally have poor scalers (if at all) and as unlike the X360 from what I remember the PS3 doesn't offer universal scaling to 1080p so 720p input would be far from ideal, the PS4 shouldn't have that problem as it looks like (at least so far) games will be native 1080p. 

It is slow for a lot of people but opinions about that are widespread. But it also has a way inferior patching-system and psn lacks cumulative and differential updates. People report many hours until a vanilla GT5 is playable. Here is an interesting thread (and in there in post #6 another one): http://www.neogaf.com/forum/showthread.php?t=520434

Yea that sounds terrible, I remember the dark days before Steam added differential patching.

this one :)

What the hell is Igavania? I googled it and still can't find a definition. I know vania stands for Castlevania and I know the term Metroidvania, but what the hell is "IGA" vania?

Buy a ps3.

Go for the ps4. Some form of support of ps3 games will come through the "classics" on the psn store. It may take a year or so, but they will come.