To me, it's an easy call. this is my favorite card i have.
Rewards Credit Card - Cash Back Credit Card | Discover
the cashback is good, and with all the promos they run each quarter or whatever it's fairly lucrative. I've stopped using all my travel cards and stuff because the points are just worthless. I just rock with cashback cards now. Just better value IMO. The IT card has been great. Only once place in the last 2-3 years that hasn't accepted it, but if you're gonna travel internationally a lot it would be smart to get a backup visa or mc.
If you hate the idea of discover, there's tons of competition in the cashback market, but
Chase Freedom Unlimited Credit Card | Chase.com is probably a good choice. I have the chase sapphire preferred travel card, and it _was_ great back in the day (points were worth a lot more), but it costs $95/yr and that's stupid.
So, I'd say focus on the following:
* Cashback
* No yearly fee