Great question (especially since I've been "going off" about "simple pistols" and such lately
)
I'd say...
-good sights (YoBo retros, Heinie, etc) since I don't shoot BE, I view adjustable sights as unnecessary on a pistol
-reliable. If that means you need a "reliability package" done, fine. If it's reliable out of the box (like my Colt 70 has been), even better.
-Good trigger. I prefer a long Greider. It doesn't have to be a "super duper match" job. As long as it's clean.
-As accurate as it must be. Once again, my pistols are for defensive purposes and fun at the range. BE level accuracy is unnecessary. Then again, I do believe that most pistols are more accurate out of the box than the shooter. Yes, my Nighthawk is more accurate than my older SA and my Colt, but I'm far from unhappy with their accuracy. It's just gravy.
-Beavertail; only if you need it. Last range trip, I put about 400 rounds down range: 200 through the Nighthawk, and 200 through the Colt. I shot the NH first and when I switched to the Colt, I had no problems, and the only "side effect" was a sore hand.
-Checkering. Nice, but not necessary. There are enough new grips out there (simonich, VZ, etc) that I could use and cost a heck of a lot less than a checkering job. Once again, it's gravy.
-High grip. Gravy. My NH has it, and it's nice. My Colt doesn't and it's nice too. However, I WOULD spring for a hi grip mod before checkering.
-Dehorn. SLIGHT. I shouldn't cut myself on the damn thing, but aggressive dehorn jobs look like shit.
-Commander hammers. (For me) Gravy. (see my beavertail explanation)
-Bevel mag well. Yes (but slight). My NH has a magwell and it's nice, but not necessary.
So, in a nutshell
NEEDS:
Good sights
Reliable
Good trigger
SLIGHT dehorn
Mild bevel of mag well
GRAVY:
Checkering
"French" borders
Beavertail
Mag Well
Anything cosmetic
FLGR
Finishes other than bluing
Hi grip mod (although it's more likely somwhere in between "needs" and "gravy". Hmmmmm "needs gravy"? Mmmmmmmmmmmmmm gravy....)
Rich