My thoughts on the demos:
NHL 2k8 - plays fine.  Maybe if I liked hockey....   It could be a good game for hockey fans.
Conan - Really?  They wanted this to represent the game?  At one point the VO even quit working.  This was the worst demo to date, in my opinion.  I thought all the EA Sports titles were bad, but this takes the cake.  
RCF: ToD - Fun.  Not mindblowingly awesome, but I think a different level may have been better as I felt thrown into a lot all at once.  This is definitely a fun action platformer, but as with most action platformers I would rather rent it and beat it than purchase it.
This is impressive considering that I never played a previous Ratchet and Clank game before and had no clue what upgrades and ammo went to what and I am still unsure of what picking up all the gear did for me, except my gun eventually upgraded.  Not having a clue what I was doing, I still had fun.  That says a lot.
I also bought Go! Sports Ski and Cash Guns Chaos.  
Go! Sports Ski is definitely a fun quick game and decent for $3.  I think the controls need a bit of a tweak, but otherwise it definitely plays better than most other games that use the controls.  
Cash Guns Chaos is odd, but fun.  Now I just wish that I could find out how much time I have left in my level, because I keep beating my targets but then usually end up dying before the time is up.  I turned the difficulty down to wuss and at that point it is almost too easy and I find myself getting bored waiting for time to run out.  I think I would do better mentally on harder levels if I had an idea of my time remaining.  In the words of my wife, "That is disgusting."  
