Yes, games is a good niche for SEO...but you'd want to be more specific...Are they flash games? Sports? Computer games? Online games? Poker games? etc...be more specific and the SEO becomes better.
It would be far easier if you picked only a game (other than cstrike, which is already too crowded) and made a website about it with tips, strategies and cheat codes. Try to pick a successful name with announced sequels so that you will be able to add new content.
Well you have to check the competition before you can call your niche a 'easy one'. To learn more read this post-- http://forums.digitalpoint.com/showpost.php?p=4068088&postcount=27
SEO it's all about how you do things. There are millions of people all over the world that love cars. I would advise to create something that you are willing to learn or that you know what you are talking about. After that optimize your website and start working on off-site SEO.
If you're talking about a niche that will be easy to rank for then games is not an easy niche for seo. There are ton's of sites that are related to games.
Definitely games is not easy niche for SEO because there is a lot of games online that is most popular. You need to be more specific in what games is it and what usually used by the users? Games keywords tends to be highly competitive and not easy to rank in the search engine.