I made it to round 43 and im sure if i wasnt so tired at 3am i could have went further. My stradegy im sure isnt too different from everyone elses. I used an upgraded thundergun only if i was completely trapped or if i wanted to reach a much needed power up. I prefer doing the inside the building loop on kino der toten in a counter-clockwise direction and i would pull out my random assault rifle or SMG that i bought off the wall and turn around and shoot the crowd of zombies only when i reached the stage( which i think is the safest area). After that i just keep running the loop dogging stragglers and conserving thundergun ammo until i know im close to the demon dog rounds. It works for me so thats what i like to do. Seems to work best on solo though.
