All the lounges we have tried are walk up and seat yourself. Off the top of my head here are the ones I remember:
Nomad Lounge - love it and go there every trip.
Tune - in - Lounge at 50s Prime Time - the drinks are o.k. and fun but it's a small space and we have never been there when we haven't had to just kind of hover at the end of the bar.
HBD Lounge in HS - another must do for us, we have always just seated ourselves, we did have one time when there was a pretty long line and a server was asking how many in each party because there were two tops available and people didn't want to cut in front of people in line to take them. We were two so she told us to just choose a table.
The Wave Lounge in CR resort - a bar and seating area, we sat at the bar and got pretty good service.
The Tabu Lounge in Poly - can get pretty crowded, we sat at the bar for a late lunch, the bar tenders were nice but busy as all heck so the service was a little slow.
Abacadar on BW - great bar and table seating as well. The bar tenders were very friendly and we actually hated leaving to go to our table at Flying Fish.
Belle Vue Lounge in BW - one of our favorites if we are staying at BWI. Very small bar and table seating. Bar tenders are always friendly, it's nice and quiet.
The bar outside of Jikos (I can't remember the name) we had appetizers and drinks here before our dinner at Jikos. We enjoyed the bar much more than the meal.
The bar area in Spice Road Tables - no sit down area but stand around tables and a bar to stand at. We were doing wine flights around the world so had one there. Great bar tender and service.
La Cava in Mexico - hard to get seating, always crowded but decent service and excellent tequila. They seat you.
Wine bar in Italy - can't remember the name, they seat you here. We have had good service and not so busy days and we have had not great service and busy days.
Tapline Craft Beer in HS (that might not be the name) Bar area that they prefer you not stand at, standing bars around the place and outside seating. You seat yourself.