...The Wave at Contemporary isn't a true "lounge", but it's a really great bar with a wonderful beer and wine list, combined with great cocktails and bar food.
La Cava del Tequila in Mexico Pavillion might just be my favorite place in all of WDW to get a drink. Not sure if everyone considers it a "lounge" but it's not a full service restaurant so I think it counts.
Great place but you can only get in if you know the secret password. Seriously, it's like Caseys, I've been able to get a table at La Cava but once I actually had to beg even though there were open tables. Something about if you stood in line you could get a place at the bar and a take out cup but getting a table was different but no directions as to how to do so.
You just have to talk to the cast member at the entrance. Last time we were there they told us it could be a 30 minute wait for a table, so we got in the to-go line. Two minutes later they asked us if we still wanted a table because one had opened up.