Well Ratchet & Clank has evolved from the PS2. If you are willing to get (or have) a PS3 the Ratchet & Clank series on PS3 is just as good as it was on the PS2. So far the games out there include Ratchet & Clank: Tools of Destruction (full game) Ratchet & Clank Quest for Booty (mini-game available on PSN and retail for EU) Ratchet & Clank: A Crack in Time (full game) Ratchet & Clank: All 4 One (full game, available in stores and on PSN) and Ratchet & Clank: Qforce/Full Frontal Assault (coming soon)
Allow me to dive into these games and answer all of you're questions. Ratchet & Clank: Tools of Destruction, Quest for Booty, and A Crack in Time are all linked in what is known in the US as the Future series, which is based around Ratchet's past and Clank's destiny. The games have gameplay that will be just as you remembered, with characters that you will know, and most importantly humor you will LOVE. However unlike the PS2 games the Future series are VERY story-strong. You thought Nefarious' vendetta against the 'squishies' was a nice story, you'll love the great plot Insomniac stirred up for these three unmissable games!
Tools of Destruction was designed very well, much like the PS2 games. It's like a true fourth game (not like Gladiator/Deadlocked wasn't great) as it seems to work like R&C3, but adds more features and has a serious graphics overhaul. The characters are lovable, the gameplay is excellent, the weapons make big explosions, the bad guy has an intimidating evil laugh, the humor is funny and the story is superb. You'll never live with yourself if you don't play Tools of Destruction
Tools of Destruction will lead you to automatically get Quest for Booty and A Crack in Time, so I don't think I need to explain how great those games are, though I warn you All 4 One is NOT like the others.
If you are open to change you could like All 4 One, don't let it's reviews put you off, it's a beautiful game. See you can't control the camera, the online play is a bit glitchy and the fighting gets repetitive, but the scenes are marvelous, the story (while not A Crack in Time) is quite good, and the characters haven't changed a bit… except for their physical appearances… but if you're a true fan you'll be able to see past all that and appreciate what a great game it is.
If you don't know much about the games (story and all) I implore that you do NOT look them up, some spoilers will… spoil your experiences. Seriously don't look up anything, not even the main characters in A Crack in Time or All 4 One! Just play Tools of Destruction, Quest for Booty and so on, and find out the galaxies greatest secrets by simply playing the game