Large scale FPSs. Games like Squad or Red Orchestra, with servers of up to 80 people. It's as much about the spectacle as it is actually the gameplay. You aren't a hero, you aren't gonna go on a 15 man killstreak and get a special popup saying what a good boy you are, you are a cog in a greater machine. And there's a sense of comradarie with your immediate squaddies.
One example was in Squad (BF2's Project Reality mod spiritual successor), Russians vs Militia (Eastern European Paramilitary Rebels, think the renegade soviet states during the collapse of the bloc). We were the Russians. Round start, my squad and a second squad were going to advance into the mid areas via BMPs and a Logistics Truck, in order to try to establish a frontline and a FOB (There are no objective spawns, so you have to set up forward spawns manually) fairly deep into the map. So we're cruising along, I'm in the back shooting the shit over local (the game has radio with squad, but also a smaller proximity chat that fades via distance) voice chat, cracking jokes, when all of a sudden an explosion rocks us and we're all bailing out.
Some militia fuck had hit us with an RPG and we were in the midle of an ambush. I was medic so I was rushing around trying to triage people without getting shot myself, throwing smokes for cover, etc. It lasted only about 4 min before they melted back into the hills, but it felt far, far longer than that, and not before they had dealt some pretty serious damage to our team (The BMPs are worth quite a lot of tickets).
Also anything with progression of individual units is always a weak spot of mine, as long as they can also be taken away from you via permadeath. One of the reasons I love blood bowl so much.