Good MMO For a Starter

A few of my friends want to get into the mmo world awaiting TESO and are wondering what is the best free2play mmo (thats decently populated) for someone wanting to get their feet wet in the genre? im curious as to what others think aswell. much appreciated

Everquest 2 and Rift are both free and have good population

Everquest 2 has the more oldschool feel for an MMO. If you're doing it to get ready for ESO, I would suggest one that has a combat structure similar to what ESO is going to be.

The game that seems the closest to what ESO is trying to do with combat (I've found) is called RaiderZ, but I think the population is mostly all on the top-end now. You can also try TERA, but the classes are more restrictive than what ESO has planned. Also, TERA's community is... quirky. That's the best adjective I can think for it. Be prepared for that if you're going to try.

Try LOTRO, SWTOR or RIFT. All big, triple A quality MMOs that have sadly gone F2P.

Try LotrO if you want a huge world and if you're a fan of the universe. Try AoC if you want stunning graphics, an active combat system and a raw sense of realism. Try Rift if you want an expansive class-system and if you are a fan of random events popping up around you.

LotrO
Age of Conan
Rift