I'd have to say I've taken a liking to Mirage too. It's a great little map, with some nice flanking routes, and a good slugfest area in the centre. Terrain is uncomplicated and easy to navigate with plenty of visual landmarks. Excellent FPS to boot, and all assets are included (I like facing a variety of threats).
Marshes and Sandblasted are old favourites too, uncomplicated, easy to navigate, good fps and good cover accomodates a variety of tactics. Though marshes at night is very difficult to play on due to the unfortunate combo of the new night vision shader and colour palette.
Extremity is good change of pace, with interesting gameplay mechanics. I'm not an huge fan of the extra building clutter though, but it does provide some nice cover and opens up some interesting ambush posibilities. Bloom and heat haze during the day is a bit overdone though.
Frostbite is a nice map (when it's not blowing a blizzard), nice rolling hills, plenty of cover and open space to have awesome long range fights and intense brawls.
I'm starting to loathe clearcut due to it's heavy system requirements. One of the nicest looking maps mind... Also don't like how the action inevitably becomes a base camp fest either.
Worst maps by far in my opinion are thunder rift and inferno. Both are horribly constricted, narrow chokepoint oriented maps. Navigation on inferno is a right pain, due to all the impassable terrain and lack of easily distinguishable land marks. The huge size doesn't help either. Getting stuck on the jaggedy terrain on or falling off the bridges into the soul consumingly dark water / lava really bites and is quite easy to do in any sort of brawling situation. Both maps also bomb out fps wise.
