I've decided to get WaW first. It has had several strong recommendations and many of my friends have it. It is similar to 4, and I adored 4, so that is no bad thing. It also has the voice of Jack Bauer
The problem with Resistance 2 is that I really don't like horror, and I have read that there are some survival horror elements to the game, and it is also more of an arcady shooter, whereas I prefer something similar to CoD