Not sure if your just asking us which of those 4 are our favorite, or really which tavern in POTCO is our favorite. If its the latter, you missed a few.
Rowdy Rooster (Port Royal)
Royal Anchor (Port Royal)
King's Arm (Tortuga)
Faithful Bride (Tortuga)
La Bodeguita (Cuba)
Ratskellar (Padres)
Skull's Thunder (Padres)
<unnamed> (Padres Beach)
I generally prefer the taverns on Padres for thier higher minimum bets at the tables. If any favorite its a mix up between these two (Ratskeller and Skull's Thunder).
I like the <unnamed> tavern at Padres Beach because the bartender will heal you if you need it while leveling up at Padres Beach.
I like La Bodeguita (Cuba) because it is often quiet, when just me and another friend want to play head to head (we ignore the computer players usually set there).
Zeppers lvl 40 - All mastered but lvl 21 cannons
Groggy McJones lvl 26 - All weapons quest/tp quest finished - avoiding story quest
http://pirates.teamofx.us