well those are two big ones and so i'm going to use at least one of them because "just PVP" is not a fair statement.
Graphics, not just the scenery but the characters. Everything looks good, has a nice crisp feel to it. as opposed to half finished looks many MMO's have.
high level raiding. This is a pretty common thing in any MMO but i never found it as rewarding in other games. Probably due to the ease with which you can do it.
I like grinding for the most part, my class is fun and it's actually fairly exciting for me to level. Grouping is a nice change and if you have chosen an AOE class then leveling is very active and exhilirating. If you pick a class you enjoy leveling then the grind isn't a huge deal.
The grind and death penalties. These are a large part of why i play L2 personally. I hated DAOC where a week of hard leveling capped your level or WoW where a month of an account and i'm near doing top level raids. When you play L2 you earn what you get rather than just havign the devs hand it to you. Keeps interest ing the game longer.
Sieges. I'm not talking about their PVP value which is also pretty fun but the fact that there is an intrinsic amount of politics in game depending on who owns castles. Castles have a reasonable influence on the server life and that's not something you get with battlegrounds or WoW semi-pvp.
Non-instanced hunting. Scarcity breeds conflict and that is the core of L2. Whether it be PVP or politicking you run into conflicts with other players. It means that once you're to a decent level you have to compete to even XP. In other game you go in an instance and be done with it. L2 forces you to compete with the rest of the player base. That means you HAVE to interact to some degree as opposed to say WoW which is the best "solo MMO" i've played.
The market. You can take a few mil at lvl 40 and turn it into a fortune. We have a real, player run (all players) economy. Depending on yoru server that could be good or bad but it is active and always moving. You can get rich or lose it all based on yoru decisions. Something you see in very few MMO's (EVE is the only one i know of with a similar economy)
some of the quests are pretty fun...this game is all about connections in my opinion...join up, meet some people, make friends and use the features ingame to stay in touch (msn messanger, in game mail system, pm's, etc)
Hunt together, build a clan together, overenchant some weapons, level up...take a castle, finish some of the higher end quests (wish potion is alot of fun, Coin Collector is good too)...raid some epic bosses.
Set goals and work towards attaining them. Theres lots of little sidetrack type things to keep you busy..lottery, monster derby...hell, raise a pet. Raise two!
Whatever you do, have fun doing it! Otherwise, whats the point.
1. Good time killer.
2. Many friends to play with on Bartz.
3. Getting known new people.
4. Joining a good Clan/Alliance and enjoy big PvPs/PKs raids, Castle Sieges.
5. Just to play it, click Bartz then OK and see your character... when you do it 78+ level with top gear without buying adena you can be proud you did it, and it's a pleasure to play this game, especially difficult class like Phantom Summoner, Abyss Walker or a Tyrant.
... Besides PvP and scenery? I feel like it's just a grind and then you PvP some. Is there some incentive out there I just don't know about?
What you don't understand is that "that" is the game.
There is no predetermined story. The game is the politics and interactions with other players. Clans hating other clans, alliances hating other alliances.
Players scamming other players who then inspire the wrath of other players. Then the scammer gets his friends and it's war. Fighting for hunting grounds, etc.
I can see where that isn't for everyone but it's the players who make the politics and the tensions.
1. Excellent roleplaying platform.
2. Economy. Messed up to all hell and all the more fun because of it.
3. People. And sheep. But this goes for any game.