MMO or offline is ok too?
MMO Games that i liked were Flyff and Digimon Masters/Battle.
I ended Flyff when i was like 60 LV cause it started to be hard to get EXP and iirc it was a grind fest.
Digimon Masters is addictive once ur into it and its a Gringfest game 100% .
You get a Digimon and LV it up,LV up ur Tamer LV and unlock new places. Some of them can be accessed w/e u want and some can be only accessed 1-2 times a day.
No PVP but ofc there are other things to do in the game. One of them is getting a new digimon.
You can pay for digimons in the premium shop or get one urself.
Find the Digimon u want on map > Kill it > Get Mercenary Eggs > Get Chips to hatchit > Get lucky andatching it > Aim for 4/5 or 5/5 Size > Brag about it
That process take a lot of time if you do it alone, but with a friend or a group its fast and fun.
So next to grinding and getting new Digimon u can enchant ur digimon get it into Burst Mode and unlock its Ride mode.
Like any other MMO u have quests and you have achievements too (Not sure if you have it in other games)
Events, some of them give you special clothes(Like the next Christmas event is gonna give, i'm sure about it), premium items and free digimons(4/5 and 5/5)
For other stuff check the game urself
idk if that's all. Haven't played it for months now. PVP is gonna be brought, idk when but the Korean server has it already.
Digimon Battle is dead. That's a shame. It had a great Battle System that you don't see in MMO games.
Offline games that i liked were:
Tomb Raider
Rogue Legacy
The Walking Dead
I'm on a hunt for offline games too
Try Rogue Legacy, its a great Indie game.
EDIT: for FPS games Blacklight Retribution was good.