There are SO many digital OTA (Over The Air, aka broadcast) channels!
You can also buy a DVR that uses your antenna (It also passes the signal to the TV). Kind of pricey, but it's a one time cost. Time shifting programs is nice, but being able to skip over ads is the real value (to me - if I don't see em, I can't be tempted by them).
I've had mine for a while so I can't recommend a current one.