UT1 bots were the best to play against. And you could easily nerf Loque's accuracy if you wanted. Those bots were pretty stupid, which is part of the charm. Watching them rocket suicide on the wall next to them, dodging into lava. I liked how the UT1 bots multidodged, even though it was slightly over the top sometimes.
UT2k4 bots were the worst. Less customization possible, very hard to nerf accuracy (on Godlike, it's always high, even if you pulled the accuracy slider as far left as you could). They don't dodge, except in response to your projectiles. Getting good hits with rockets was difficult, unless you were so close you also took splash damage. Hitscan dominates the bots far more then it does online.
UT3 bots were an improvement. They aren't aimbots with the link shaft and actually miss with the flak. They move around somewhat too. The problem is the bots extreme aim. Instagib is unplayable, unless you like being shot from strange angles so accurately every 5 seconds. Oh, and no customizations possible (haven't tried mapmixer yet).