I've only played Psi-Ops from the bunch. I just got Ratchet and Clank 2 from Gamefly today but haven't bothered to play it. Psi-Ops was pretty good but it's short and the last few parts of the game sucks. Weird selection of games though...two platformers and an action game. Sorry I can't be of much help here...
Despite all the R&C worshiping on this board I cannot help but maintain that I find Jak 2 to be more enjoyable game. It's just more interesting and involving, not to mention that it's better looking, controls feels tighter, and has much more interesting story. I started playing R&C2 the other day, but it just not calling me back. Then again, as I've said *many* people on this board prefer R&C2 over Jak 2. Psy Ops, I've only played the demo, and thought it was pretty fun, so I'm considering buying the game. It has very nice implementation of the physics engine, which lends to some inventive puzzles that I've never seen before. For example:
You can use telekinesis on almost any moving object in the game as well as enemies, but not on yourself. However, you can stand on a plank or any other object for that matter, then use your telekinetic power on the plank to levitate both the plank and yourself over the large hole on the bridge. The best thing is - that is just one of several ways to cross over that hole, you can be quite creative in your powers usage