Let's see...
Heroes of Might and Magic. That game has gone into a downward spiral after HoMM3. HoMM4 was just wierd (and not in a good way), HoMM5 was kinda crappy (likely due to an inexperienced studio and low budget) and while HoMM6 does show signs of improvement, I refuse to buy it due to Ubisoft's DRM.
I was a bit worried about Total War since Empire was a mess and Napoleon outright sucked (at least to me), but Shogun 2 got them back on track.
Bioware's single-player RPGs have been on the decline lately, going from "They can do no wrong!" to "A few mistakes in an otherwise good game" (Mass Effect 2) to "WTF is this shit?" (Dragon Age 2). Needless to say, I'm more than a little concerned about Mass Effect 3 and even more about Dragon Age 3. And I have no idea what to think about the whole Command & Conquer thing...
Dawn of War is also worrying me. It started as an amazing RTS, had one solid expansion (Winter Assault) followed by a big stand-alone expansion which will be forever remembered as one of the best RTS games ever (Dark Crusade). Then they followed it up by a terribly crappy Dark Crusade ripoff (Soulstorm). The sequel, while not terrible, just lacks the sense of scale and scope of the original, focusing on tiny squads and an overabundance of RPG elements. I hope they get back on track for DoW3...
World of Warcraft is just ridiculous by this point. While I don't play it anymore, I do keep track of what's going on in there and from what I can see, the game is becoming a parody of itself. I'm sure this is fine with a lot of people, but having grown up with the Warcraft games, it just rubs me the wrong way to see that universe treated like this.