I guess UO was the first classless MMO that I can think of, you had 700 skill points to allocate. I don't know if they ever changed it over the years but that's how it was when I played. I guess the EQ was the first MMO that really had classes other than the old Neverwinter nights on the AOL game. Then DAOC had a multitude of classes.
I guess you're right though that Eve was the first game where you could learn every skill. I always forget about it just because it's just such a different game.
COH was a bit more free form with being able to pick different power sets based on whatever class.
Fallen Earth was more of a UO style system.
TSW was honestly the first regular MMO where you were running around with your character, and not piloting different spaceships where you could flip between whatever skills you wanted, and definitely more of a traditional MMO layout with quests, dungeons and shit.
I'm sure there are single player games and maybe some survival sort of crap that might do that, but it's not like a whole ton of MMOs come out anymore other than gaysian shit or ARPGs.
I think that's why we played it for so long and enjoyed it so much is because TSW was pretty unique with the skill wheel. Hey if you didn't like whatever type of weapon and abilities, no biggie start leveling up something else. Probably the closest successor to that type of system sounds like New World. I've not ever played it, but I'm tempted to fire it up for the first time, especially hearing about some of the guys talking about the new expansion.
Honestly wonder if I have a free copy of it via Amazon prime or something, or at least a big discount?