Although I dearly love my 17HRM, and I shoot it a lot, I voted for the 22lr simply because of the cost of ammo. I can get so much more shooting for the same ammount of money. I don't own a 22mag or 22 Hornet, so I can't comment on them.
The 17HRM has been much more effective on the common yard varments I shoot hee. Cats, Possoms, Skunks, the ocasional Dog or Coyote. I don't shoot much more than the above, other than Gophers, and I use the 2wlr for them. And ocasionaly, on a good day, I'll use the 45-70 for Gophers. It does a great job, but might be a bit of overkill on them.
Greeenriver