So, just talking about it in the Recent Purchases topic, figured I'd start a topic for this all on its own. As the title says, talk about what series you're kind of a slut for.
Now, keep in mind this isn't about "favorite" series necessarily. We all have favorites, obviously, but oftentimes they remain favorites because they never seem to fail us. So, for example, I won't be mentioning Ratchet & Clank, because not once have I had mixed emotions about any of its releases; it's a favorite because it really has been great every single time.
No, a "slut" series would be one that may sometimes falter, may burn the hell out of us at certain points, but we still just can't help but to buy into it every time. So, y'know, probably something with excess of four releases (because otherwise, how would you even know?).
For me, as mentioned in the recent purchase topic, I'm totally this way for the Assassin's Creed series. It wasn't always like that; I played the first game when it initially came out, and though I liked it a bit, it didn't really grab me like it does now. It was only years later, when I finally tried out AC2 that I got hooked. It was around the time AC: Revelations came out, so it was four games in at that point. The original game was a bit "blah," but then I played through the entire Ezio trilogy for the first time back-to-back and absolutely fell in love. So of course I was hyped as hell for Assassin's Creed III when that was announced... and when I finally played it, I ended up pretty goddamn disappointed. It's not an awful game; it has a lot of quality floating around in it, and introduces some great gameplay ideas. But it has the absolute worst protagonist in the entire series, and a storyline that utterly fails to live up to the potential of the game's American Revolution setting. Despite some great ideas, it felt like such an ugly misstep.
And yet, I still happily showed up for the next game (Black Flag), which turned out to be amazing. Then two games were announced for the next year: Rogue and Unity. Played Rogue first and loved it (grossly underappreciated game, that one), but Unity was another misstep, like ACIII. The story failed to utilize the French Revolution setting in any particularly compelling way, the characters were mostly a bit bland (although nowhere near as terrible as Connor from ACIII), and the gameplay felt oddly wooden, with a totally revamped battle system (which was faaaaar less fun than previous games) and parkour that felt clunkier and looked sillier than it ever had been before. Not the worst of games, and it does have some merit regardless of anything, but it'll never be a favorite. Not by a long shot.
And yet, I still remain undeterred by the series. Just got Syndicate and it's great so far, fixing almost everything that wasn't so great in the last one, so the series has roped me back in. And even back when I played Watch_Dogs for the first time, I got interested to do so in the first place because I'd heard about certain intriguing connections it has to the Assassin's Creed games (though I ended up loving that game for other reasons entirely).
I think it's just because the series has so much potential... there are so many places it can go, so many things it might one day do, that just the idea of these possibilities keeps me hanging around. Even if one particular entry is a bit of a stinker, there's always the potential for the next one to be amazing, with a new setting, new characters, and new gameplay features to distinguish itself from the rest. It's always changing, always evolving. So yeah, I'll keep buying into it, just like the little slut I am.
So, any others? It could be a cohesive series, or it could even just be a certain genre or type of game, or a company. Anything goes, so long as you just can't quit it, regardless of the bad ones.