Best cs:source mods?

I'm a bit fed up with cs2 at the moment, and I noticed that there seems to be a large ammount of mods for cs:s.

Could anyone recommend some high quality ones?

I'm interested in big overhauls, weapons, skins, maps and most importantly some ai improvements to make it fun to play single player (I heard the ai is already decent in source compared to cs2 and go, so I have high hopes).