Okay, first, Trigun and Rurouni Kenshin would have to go on the Adult Swim block just for content. I love both shows and either would fit into the AS lineup just fine.
Never seen Dual, El Hazard, or Tenchi. Have a slight DB aversion.
Sailor Stars- rumors of the ending to this make me a bit apprehensive. Why is it that fantasy romance shojou never end well?!
More Gundam- fine, but one at at a time. Don't drop G, X, and whatever else together all at once.
Magic Knights Rayearth- Good replacement for Sailor Moon. Might take some time to settle in.
Martian Successor Nadesico- I don't know. I didn't much like this and it's really more of a sci-fi sitcom than a kiddie cartoon. And the Gekiganger business was just plain bizarre. . .
I wanna see Slayers!