I\'ve only played R&C so I can\'t comment on the others...
Ratchet & Clank then : it\'s a great game and all, but it just didn\'t captivate me like Jak & Jaxter did before it. Maybe it\'s the staccato gameplay (go to planet, do dis, go to another planet, do dat, lather, rinse, repeat) that turned me off, there wasn\'t this sense of a coherent world(/universe) to explore as in J&D. The controls are also a bit on the dodgy side, especially when it comes to some fierce battles. And all the weapons and gadgets don\'t feel as much an integral part of the game as I think they should, still there\'s some initial excitement to be found when getting new stuff.
Still, there\'s loads to do, pretty graphics, nice music (I loved some of the earlier tunes), it earns a healthy 7/10 from me. If you haven\'t played platformers in a while and feel like you could do with some jumpin\' & shootin\', you can\'t go wrong here