It's a tough call most of PS4's biggest titles aren't here yet so I think it depends on your patience level. Long term (just my opinion) I think PS4 will have the bigger and stronger library of games seeing how things went down with the PS3 and XBOX360.
This year's E3 will tell a lot of the story though so if you are on the fence you may want to wait till then first. Sony has had financial issues so they still need to confirm some of their big name games first to know for sure.
Really it's a personal preference thing though. If you like sci-fi and shooters XBOX goes more that direction, same with online. Playstation is more adventure/story driven games and RPG historically. That's not to say you won't see good variety on both though.
A lot of the best games will be multi-platform so you'll be good with whatever choice you make. If you like XBOX better now you can always buy a PS4 later. I see PS4 as a better long term investment and that's the one I bought. It's your call though always buy for you first though regardless of what others are doing...
