Well I have thought about it long and hard and I think the Nickelback songs I am listening to most are 'Breathe' and 'Cowboy Hat'. So I guess they must be my recommendations They're all pretty good songs though.

Also, since you mentioned that you were a fellow riff ***** you might check out Lost Prophets - Shinobi Vs Dragon Ninja, it's got a pretty cool intro. The intro is the best bit though. While I'm on the subject of riffs, there's a pretty cool bit in Machine Head - Davidian, nearish to the end of the song (I just checked and it's at about 3:38 into the song).

Well there are more cool riffs I could come up with if you want, but I'm not sure how metally you like your metal, if ya know what I mean