Oh man are you going to get a mixed bag of varying opinions here. It really is going to come down to the type of maps/weapons you like....But... If you want to check out some good ones, you might check out Mazzic's mazzic's map paks. There are many good ones in those, at least in my opinion. Once you dl them and install them, just go into his server and play the rotation, you will see all of em. Besides those I also like Thunder 2.
http://www.mazzic.org/maps.php