K2 ZED 4.4, Diamondback Response, Nishiki Colorado
 

So my choice for my first mountain bike in years with a budget of around $350 is the following:

K2 ZED 4.4 from sportauthority for 379
Diamondback Response from Dicks sporting goods or sports authority for 350
Nishiki Colorado from dicks sporting goods for 350

I am new to biking, so any help would be appreciated as far as which is the best value. I am not going to be doing any hardcore stuff, mostly dirt trails and roads. Thanks in advance. Also, please let me know if you think I am missing something that would be a better fit!