I just have the rewards direct deposited into my checking account when I've earned the minimum payout. I've been burned by rewards programs suddenly changing / being discontinued, so I figure I'd rather have the cash in hand and start working for me.
For example, Discover seems to keep randomly changing the minimum amount of rewards you need to cash out. I've seen it be $20, then $50, then to whatever, then $25, and now it's back to whatever.
As far as airline miles, I know the airline will always take my cash to pay for a ticket, so I see little value in trying to build up miles hoping I can use them for a specific flight I want.
I just switched a couple of months ago to the Citi 2% card and it's been good so far. Still use the Chase Freedom and Discover for the 5% categories, though. Ended up with $96.42 in cash back last month. I lucked out last year when Discover offered me an extra $100 bonus if I spent $500 on the card per month for 5 consecutive months. I just switched my utilities to bill against that card and voila, free $100!