There are some alternatives out there. One is to use vinegar in your rinse cycle (too much trouble for me,) and another is to use a dryer ball (controversial, since most are made from PVC-- anyone know any that aren't?) I go for the simplest of all methods. Use nothing. There.
Pros: Less chemical-infused clothing and air, less skin irritation, less packaging waste. Oh, and I haven't mentioned yet that using dryer sheets causes unecessary wear-and-tear on your dryer if you don't wash your lint trap (and possibly a fire hazard?)
Cons: Static cling. (Did you know though, that most static cling occurs in synthetic fibers? Use natural fiber clothing, and it won't be such a problem!) My laundry doesn't smell nice. But as long as it doesn't smell at all, I'm okay with that.