I like the 100 grain bullets in .243, but around here some guys are having good luck with 65-67 grain bullets in .223 (I know, I know)
If a 65 grain bullet will work for deer in .223, there's no reason why an 85 grain won't work in .243. The most important part is putting the bullet deeply enough into the vitals. I've been toying with the idea of that 85 grain Barnes TSX for my .243, but haven't had the time to do anything about the idea. Maybe this summer.