I agree with wouR, no radar, air strikes etc was a lot of fun. Perks should have never existed to, especially martyrdom

. I think CoD2 was the best of the ww2 cod's so far with UO a very close 2nd, was big time into rifles only back then. WaW is a good game don't get me wrong, the maps look very nice, but the rifles just don't feel right to me, hardly any recoil on any gun too. Cod4 seams to run more fluently and less choppy than WaW.
You can get player made zombie maps for the PC users, good place to find some are Customcod.com ( I HIGHLY recommend you try nazi_zombie_dead_sand ).
Could go on... But I won't. All good games in their own ways, comes down to preferences. If you've only tried WaW I'd recommend trying any of the others and see what you like most.