Mangler has just unlocked Kunark, so all that is available there is Classic and Kunark (not strictly year 2000 gameplay - many modern improvements exist). Expansions unlock every 12 weeks. Selo's has just unlocked LDoN, has accelerated xp, much faster expansion unlock rate. The other TLPs are in various expansions, I dunno for sure individually. Xegony and Luclin are considered the (relatively) high population normal Live servers, according to recent DBG statements. Firiona Vie for faster XP and (almost) all loot being able to be traded. Zek for PvP I guess?
Depends if your subscribing or playing free. You have to pay to play any of the TLP - the rest are free. Just start a character on what sounds good and if you don't like it you can switch.
