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.