I know EXACTLY how you feel. Gaming droughts are the worst and then all of a sudden, 4 new games come out right around holiday season.
Everytime this happens, I usually go back and clean up some achievements on older games. I just replayed GTA IV to get the "Liberty City Minute" achievement which was actually a blast.
I also download and play some DLC's that I have either forgotton about or have put off until I had some free time. Ive recently downloaded the Revelations DLC, Arkham City DLC, and the Gears 3 DLC because they all have campaign add ons that can really be great to play and a good time waster. I love campaigns.
You can also never go wrong with Arcade games! Except Call of Duty Classic.. That game on veteran difficulty is the hardest thing I have been playing.
I checked through the Xbox game marketplace and found Arkham City for 30 bucks. It was 40 something at EB Games, and that's used, so no Catwoman episodes. Needless to say, I was stoked to pick up a game I wanted to play for over a year.
Also, try searching around Amazon for really cheap used games. I got the Saboteur for 2 bucks. It cost more to ship to my house than buy.
Lastly, when in doubt, achievement hunt some old games you have. Games like the Dragon Age series are always fun to come back to.
Mostly I play battlefield or minecraft with friends but recently I've tried to 1000 point assassins creed 2 I'm only 3 achievements away the one I'm really having trouble with the feather achievement as I have collected 99/100 (using achievement hunter map, big help) so now I have to go back and check all the locations again until I find the one that I missed
I haven't had as much luck as you so far I've checked the villa and Venice I'm trying to build up the mental strength to check the rest of the cities tonight I thought I saw it in Venice so I was jumping for joy but then when I reached it I saw that it was a chest which led to one of my worst rage quits
When in a drought I usually go back to older games that can just be played to simply have fun and get me amped for the release of new games. Most recently I went back to GTA 4 to get the 100% completion achievement which I have yet to get. Going back and playing GTA 4 again reminded me how fun it was and has got me excited for the release of GTA 5 whenever that may be. I might be going back to Borderlands sometime soon.
I just started playing Skyrim today (why did I wait so long?!). Every time I need a new game and nothing is close to coming out I turn to really popular games that I just for some reason missed or if there isn't one I will replay a favorite of mine, like BioShock 1 and 2.
I typically play Just Cause 2, go through the Halo: Reach Campaign on Legendary (It can play like a movie, if you try hard...), get some new cars on Forza (if you don't burn it out, it can be quite fun - try drifting), Gears of War, or an online game with some friends (Co-Op to prevent Rage Quits)
I'll usually go back and play Mass Effect all the way through. But a great game actually just came out that I'd recommend: Spec Ops: The Line. It's a great game, I'm actually doing a review of it (but you probably don't care about that, so just check out the game) It's interesting to see a FPS beat out Silent Hill 2 as the most psychologically peircing game.
Wonderful game to play when you're stuck in this situation would be Arkham City. Amazing game to go through, and even better in new game+ and the challenge modes. Never gets tiring watching Batman clear a room like nothing x)
I like to go back and play sandbox games, sometimes I Achievement Hunt in them sometimes I just go on massive killing sprees. If it's a longer layover I tend to play F:NV or one of the Dragon Age games.