For me it's Diablo II. Granted I've played my fair share of D2 since launch, and also recently on a private server with a comrade from hexbear, but I still feel like years later the game didn't grab me as much as D1 did.
Granted I don't hate D2, but for a game that I keep coming back to, D1 takes the prize.
Lords of the Realm 3. I have no idea what they were thinking making everything real-time. Custom games were still fun for pitched battles, but the city management portion was yucky. They even had cool mechanics going on like different lords to put in charge of counties giving different abilities.
Heroes of Might and Magic VI. Five was one of the series' best entries. I couldn't even get VI to load without crashing. My fault for buying Ubisoft.
Call of Duty was a breath of fresh air when it came out in 2003. CoD2 improved the campaign, but had some mid multi-player. CoD4 was a decent "not Counterstrike." Everything has been downhill since. Moving from WWII to present day was also a mistake and I blame CoD for white supremacists taking over online spaces. At least in Battlefield, people used to get banned for slurs. By CoD4, servers weren't even bothering anymore.
Speaking of Battlefield, 1942 was GOAT. Vietnam was okay, but felt more like a mod (chasing America out of Hue was based, tho). Battlefield 2 limited how many bots you could play with...which defeated one of the main reasons to play. It's all been downhill from there and they jumped on the "Modem
WehrmachtWarfare" train after CoD started getting that DoD fed money.There's more, but these were my main focuses of hate.
Yeah what the fuck happened with HoMM 6?
Second only to 3.