Nomad is fantastic. Very relaxing, lovely views. However, my last visit was before the Pandoraverse opened, so I'm not sure if its tranquil nature is no more.
Other favorites: the Tune-In Lounge in DHS, Tutto Gusto in Epcot (if you can get a seat), Dawa in AK, Territory Lounge in WL, the bars in both the Wave and California Grill, Mizner's in GF (bland atmosphere, but very stiff drinks), Top of the World, and the outdoor waterside bar at BOATHOUSE (in good weather). Special shout-out to the Swan/Dolphin lounges, all of which have great beverage programs.
I've not yet been to Trader Sam's or the AbracadaBar but both are on my list.