So here's the thing. I have been a Halo fan since the first Halo came out. I have all six games, including Halo Wars and Reach. But I never heard anyone in school talking about Halo. They were always talking about "Duty." So I thought I'd try it.
I bought Modern Warfare 2 and WaW and thought they were both okay, but a little too realistic for me. I prefered Halo because it was something I couldn't see whenever I watched the news.
But then on Black Friday this year, I saw the game that I had been wanting forever but it was so expensive I didn't get it: Fallout 3. It was only $10. I bought it and instantly fell in love with the series.
When Black Ops came out, I decided to rent it this weekend (since I'm snowed in anyway) and I finished it in three days. Honestly, it was the best CoD game I had ever played.
I like Fallout better than Halo and Halo better than CoD, but I definitely recommend Black Ops as a definite buy. I haven't tried New Vegas yet, but I've heard good things about it. Knowing Fallout, it's probably not something you could just rent and play for a few days.
I recommend Black Ops if you're just gonna buy one, and, even though I've never played it, New Vegas if you're gonna get two. Reach is awesome, but I just thought that Black Ops is an incredible game and the makers really outdid themselves.