Here's a few off-strip places we frequent. We also go to the Strip but I'm not listing those places. Not everyone in LAS frequents the Olive Garden....

AYCE sushi--Goyemon is the bomb. Be prepared to wait.
Sushi--Kabuto
Japanese other than sushi--Raku
Thai other than LoS--Chadda Thai (really recommended; terrific lunch special); Le Thai
Dim Sum--Cathay House (I also kind of like East Ocean)
Pizza--Settebello; Grimaldi's is also pretty good.
Hamburgers--Bachi Burger
Higher End--Todd's Unique; Honey Salt; Vintner's Grill
Pub--Hops and Harvest looks good but kind of soon to tell
Vietnamese--Lemongrass (lots of contenders here; no real standout)
Mexican--Mundo for higher end
Steak--Andiamo's at the D; the Barrymore