matt wrote (my comments interspersed):
replace face (when it works, it simplifies things a lot) When you can use it it's magical, wonderful, indespensible.
move face (best for imported solids) I'll have to look into this one. SolidWorks Help isn't very helpful.
fill surface (this is like a magic wand, I love this one) I like it too, when I can use it, which always seems to be not nearly as often as I'd like to use it.
extend / trim surface (extending is sometimes quirky) Quirky it is at times, but Trim less so than Extend. And Extend I use almost as much as Trim.
delete face (this is another underused gem) This is good, but Delete with Replace or Delete with Patch doesn't seem to work very often.
untrim (sometimes this will get you out of a bind easily) This one is Black Magic -- don't understand it at all, but it works wonders at times.
delete hole (really just untrim) Never even heard of it -- need to look into it.
move body (when cheating counts and offset doesn't work) Have seen many references to this lately, and I still don't have a clue.
delete body (not sure about why/when you should use this) Ditto, but I wonder if one can use it instead of Hide Body when you actually want to do it permanently.
cut with surface (a huge favorite rather than extrude up to) INSTEAD OF? How?
up to surface end condition (sometimes you gotta use it) Yeth, but am often frustrated by the inability to use if the surface doesn't extend beyond the sketch. I often have to use Extend surface or Ruled surface to make the boundary bigger.
up to body end condition (when up to next doesn't work) I never think of "up to next" as something preferable to "up to body"
-- can't figure how that works, but I'll try it. I do sometimes wish there was an "offset from body".
loft surface (use this frequently) Goes without saying, but so many options are confusing, and many of them very quirky (often much better than lofting a closed profile into a solid, however). I'm NOT complaining about too many options . . . just that there's too little explanation, as is true with almost ALL of the surfacing options.
loft a solid between surface bodies (usually as a workaround) Didn't know it was possible.
ruled surface (quirky, but essential) Extremely useful -- I find it strange that you can use a face of a solid with this option, but not with Extend (have to Offset with zero distance first to use Extend).
radiate surface (when radiate won't work) Huh? Nothing else does what this does . . . I don't know what it could possibly substitute for.