I played the first one when I was very little, and haven't remembered much of it. Now I'm in the middle of A Crack in Time, which is the second one I've played. Would it be worth it to check out the other PS3 one, or is this one sufficient? And what do you guys think of the series? I find the wackiness, levelling system, and combat to be very awesome.

Hahahaha, when you were very little. Mocking your young age aside, do pick them up indeed, they are muy excelente.

I love the Ratchet and Clank series. It was a very big reason I bought a ps3.
The first 2 are among my favorite platformers of all time, the 3rd one I bought but I only played for a little bit. that was more because I had just recently played the second one, and by that point I was all ratchet and clanked- out .
Still haven't bought any of the ps3 versions (played the demos though and I enjoyed them) cause I am a cheap ass. I'm convinced I am soon gonna see Tool of destruction available at amazon for $10 or somewhere else, so I keep waiting for that price

^^This. Emphatically.

I picked up the first one pre-owned a couple days ago. Good so far, but I hope it's not too short. Each planet doesn't have much to do, but at least I guess there's a variety of environments.
Unfortunately, the game started stuttering badly and ultimately froze during a cutscene showing a soldier under fire. Tonight I'll try cleaning the disc to see if that fixes it, otherwise I'll return it. However they only seemed to have that one copy of the game (pre-owned or otherwise) in the shop. :(

I love them all. IIRC there was a Clank spinoff on the PSP, that was really good too.

I find the games good, but always missing that little something that takes it to greatness. For example, it hasn't really changed much since the first, and there's not so much variety in gameplay. The series has become, not necessarily stale, but maybe a bit too safe for it's own good. Personally, I enjoyed Insomniacs PS1 platformers the most - that is, the Spyro games. That was more about platforming and exploring and less about shooting. Now, when the PS2 came out, Insomniac created Ratchet and Clank. After Jak and Daxter, which was much better. Naughty Dog became the better developer with their Jak games, even if the Ratchet games were good as well.
PS3 was the first generation of consoles where they went in seperate direction. Naughty Dog went with the third person action/adventure in Uncharted, put it all in one basket and won gloriously. Insomniac's first game was Resistance, which gathered okay-ish reviews, and then secured an income with the Ratchet games.