I love COD UO...play several hours every night now during the summer.
I have never played CS....not into modern warfare as much and SWAT style stuff. Although....I think I would give a COD version of modern combat a try. The new COD2 will be very good I am sure. I personally cant wait. I agree with AGCent that a GOOD pacific theater version would be nice! If you are still playing COD UO come check out my server...listed as

aa WD Black 44 Platoon

Take care.