For most plastic to plastic bonding, I use Testors liquid cement, for stronger plastic to plastic bonds, I go with their tube cement.
For load bearing assmblies, I go with the superglue.
If I have unlike materials, I usually will go with the superglue, but if I have large enough contact surfaces on the parts, I'll go with 5 minute epoxy, Elmer's usually, but I'll grab Devcon when I can find it.