In states that don't have wacko cartridge restrictions coughIOWAcoughcough if I had to choose it would be either of my .260 Remingtons. One is a River M77 MkII in a Boyd's laminate thumb hole stock. The other is an 18" MGM barrel for my TC Encore. Interestingly, both guns prefer the exact same load. 44 gr of IMR4350 behind a Hornady 129 gr Interlock with Rem 9 1/2 primers in Lapua brass.
In Iowa, where I currently reside, my favorite has been a .357 Maximum for the last 8 years. This year I expect that to change to the .350 Rem Mag that I'll be using in a center grip XP-100 with a 16" bull barrel.