Are we talking one single weapon? If that's the case a Mosberg 590.

If we are talking what is our arsenal here we go

On my person at all times my Sig P229 .40cal
With me when I'm moving about and whatnot M-4 (w/ Surefire and PAQ4 mounted on the rails) with at least 4-5 extra 30 round magazines and the Mosberg 590
At home an M-14 EBR with an ACOG sight
Other "tools of the trade" Cold Steel Kukri Machete, a Gerber Multi-tool, My Gerber Switchblade, and just to make my brother happy a flare gun