Im looking to start back up with them after I had a dream about everquest days last night. What currently is their best game ?
Tough call, though you could go for Vanguard as it's F2P and follows the EQ1 style.
Is it? I know the population went up a bit not long ago when the class/race restrictions were removed from the game. Haven't touched it in awhile myself. Otherwise you're stuck with Wizardry Online(Permadeath), Planetside 2, Everquest 2(Which people say is worse than Vanguard, but more populated on a few servers), or DCUO(Superhero fun time).
The site is saying the main server is at medium population too, though I don't know how many people that would be.
I would say go ahead and give Vanguard a go. It's a great game and the population was decent last I looked. Not incredible. Based on the recent changes (removing all leveling/race/class restrictions for F2P characters, allowing F2P players to have houses, etc...), I would say the population is continuing to rise atm.
Other than that DCUO is probably the most populated at the moment. I have heard good and bad things about Everquest 2. People say its not near as great as EQ was, but at the same time I see a lot of people saying they play it (and enjoy it).
Of course, if you're not looking for an MMORPG, Planetside 2 is definitely a great option.
stay away from eq2 unless you want to subscribe, the game got butchered really badly.
vanguard is GREAT if you love games like eq, though.
dcuo is overall really fun, too.