Indeed looks epic, hopefully much better than the 2nd. First was amazing, 2nd was boring.
So skip them and just go straight to this ?
First one is worth playing (if you want to play it on console I think it was released last year as a downloable game on XBLA and PSN), I would skip the 2nd and just read about its story on Wikipedia to know what happened
Are you playing them on console or on PC?
If you've got the rig to support it, I would DEFINITELY pick up both previous versions, before you play Crysis 3. Second one, while not stellar, was still one of the best shooters around when it came out. Wide open world, plenty of challenge, just a fantastic game.
In fact, if you DO have a PC that can handle them, PM me, I'll give you my copies.