A 20 year-old Tawny tends to hit the spot for me, when I'm in the mood to pair port with something. Graham's, Nieport, Ramos Pinto seem to be readily available and good.
Honestly, among sweeter libations, I might suggest a nicely aged rum more than a port to go with a cigar, based on my early experience. For pipes, something like a whiskey seems more natural. For a supreme treat, I drink Balvenie 21 year-old Portwood with a 10 year-old GL Pease English.