Highest Priority
-Must use Renewal stat system, refinement system, monster spawns, etc
-Must allow dual clients
-Must have autoloot, alootid, warper, job changer.
-Should be non-PK server.
-Any server that had a wipe in its history or is planning one in the future is a no-go.
High Priority
-Rates of 10-200x (exp), 10-50x (items)
-Must have fully functional 3rd classes
-No donations preferred, but if there are donations, they MUST be tradeable so you can get it by buying from other players, and can't be overpowered.
Low Priority
-Renewal costume system and mounts should be available
-Low cooldown on ET is preferred
-Should have a reasonable sized populaton. (50 is ok, 200 is better, 10 is not ok)
(Don't post CookieRO, cause I'm already playing there.)
Alternatively, a fully customized server with custom still trees, skills, classes, races, stat systems and damage formulas, monsters, etc that is balanced is something I'd also be interested in trying.
Anything goes as long as it doesn't use pre-renewal stat systems, monster stats and damage formulas, and is better than normal RO.