I hate the game, because at the time of the first, and even the second title in the series, it had so much potential, and it was a really fun game. By the time 3 came out, I was getting real meh, and while 4 was a rejuvenation of the series, they started whoring it out, excuse my French, and releasing a new game every year. Dev was rushed and the gameplay suffered for it. World at War only stayed playable for more than 5 weeks because of Nazi Zombies, but if I wanted to face wave after wave of unintelligent enemy, I'd play Left 4 Dead. Modern Warfare 2 was okay, at best, because it had I-dub behind it (Can't say they're not good storywriters) and a fun campaign. But multiplayer went pretty stale for me after the first 2 months. Now, Black Ops, the 4th game within 3 years is gonna be released, and it looks like it's just a reskin of MW2, with a poorly-written story, and some pretty badly-contrived goodies to try and make it fun again.
Honestly, if you can't spend your time making a game people won't get sick of in a few weeks, you shouldn't be making games. I gotta say Bungie has some -blam!- good work, considering it's been 9 years since Halo's initial release, and people still play the original. Hell, Halo 2 is 6 years old, and it was so played, even after 2 more Halo titles were released, people were actually saddened by its removal from Xbox Live. Halo 3 is 3 years old, and is easily the top-selling Xbox 360 title, with countless people playing it, even today. Call of Duty 4 was released 2 months after Halo 3, in prime position for the '07 Christmas Rush, and didn't see sales numbers reach as high. In fact, it's never been played as much as Halo 3. Now, Reach looks to take Halo 3's slot, but don't count the latter out. It'll still be a very popular game on Xbox Live, and even after it leaves its XBL run.
Why? Because Halo's created an iconic role for itself. It's got multiplayer anyone can pick up, but still leave the "pro" gamers with a fun time. It's got an insane campaign experience that rivals Star Wars in terms of epicness. (In fact, I daresay it's my generation's Star Wars) And, for god's sake, it's a quality game. At least 3 years on each of the titles. That's better than the 1 or 2 on a Call of Duty game, I'd say.
Now, don't get me wrong. I had a great time playing Call of Duty. I enjoyed it quite a bit. But, it just got stale in a really short time. And, while I anxiously awaited Modern Warfare 2, for its development, and continuation of the first MW's story, I have no such desire for Black Ops, because it lacks that story, and merely borrows a used game engine.
(If my use of the word "whoring" has offended anyone, please let me know. I don't mean to transgress against the language use rules, and if I have done so, I will gladly change that to some term you deem more appropriate)