Battlefield...specifically Bad Company 2...and THANK GOD I DID!
Battlefield has become my favorite mutiplayer game of all-time (followed VERY closely by Halo)
You have to understand that before Bad Company 2 my multiplayer time consisted of Halo, Gears of War and Call of Duty. So I try the beta/demo of BC2 in early 2010 featuring the Rush game mode and kinda hated it. I didn't care for the gunplay or for how loud and crazy the gameplay was with all the explosions, destruction, mortars, vehicles, etc..It was just too hectic and I was rolling solo. I think I only played one round and decided it wasn't for me.
About a week or so later the game launches and I notice a group on my friends list playing it every night. After a week or so I pop into their party chat and ask what it is that they like so much about the game and that I tried it and hated it. I will always remember one dude saying to me, "Thats because you are only used to playing Halo and Modern Warfare. Battlefield plays differently and has bullet drop, you need to lead your targets, etc. It is meant for you to play a role in a squad and ptfo. Get the game and play with us and I guarantee you will learn to like it." All the others in the chat chimed in and agreed.
So I immediately go buy the game at Wal Mart - it was almost midnight - get home and play with my crew for a few hours and my eyes were opened to the absolute GLORIOS gameplay of BATTLEFIELD! I fell in love, became a YUGE fan and convert that night. I would end up not playing Call of Duty again until Warzone 10 years later.
I have no idea how many hours I have spent playing Battlefield over the last 11 years but it has been absolutely awesome the whole time and I never get tired or burned out. I regularly play Bf4, Bf1, BfV and I can't wait for BATTLEFIELD 6!