Yeah, the maps were pretty amazing on BO - you had the likes of Summit, WMD, Grid, Firing Range, Array, Radiation and even Nuketown and then the DLC maps like Drive In, Hotel, Kowloon, Stadium, Hanger 18 off the top of my head. Not only were the maps nice and varied but they worked incredibly well in all the modes on offer. Even utter crap like Crisis was pretty good for Domination, CTF and SnD.
Pity we don't see that consistent quality now and Treyarch seem to be too focused on this 3 lane shite and making maps the sizes of shoeboxes. Even the larger ones from BO were great as they enticed players into key areas and you could be more tactically creative with flanking. Now it's just a nade spam fest and matches being done and dusted in minutes with mindless shooting. You had to work for your kills and the win in BO.