Guinness, Old Dominion makes a great oak barrel stout and Saranac Caramel Porter are probably my top 3 favorite beers to compliment smoked goodies. (Arrogant Bastard or Arrogant Bastard Oaked are also good)  In the summer though, I keep it light with an IPA or even Bud Light Lime.  Oh yeah, Troegs makes a brew called Dead reckoning that also goes well with smoked goodies.  (basically stouts and bocks are best to me...)
Oh yeah, I do also like spotted cow, but not necessarily as a smoker compliment.
BTW, I tried railbender and hated it.  Too much like a barleywine to me...