If you feel like spending, i *highly* recommened Cutty Sark 18yr. As far as smoothness goes, in my opinion (and my dad's and my friend's whove had it), smoother than blue label, ballantine 17 yr. (althose those are very good too!)
I'm not sure how much it costs, but Black Label is also an excellent choice! (it's the lowest in the Johnny Walker Range after Red Label) Red Label isn't too bad either, but I have my whiskey with ice and soda, so...
If you do feel like spending a decent amount, Gold label, ballantine 17yr, chivas regal 18yr are very nice

If you want to spend an exorbitant amount, blue label, ballantine 21yr, cutty sark 25 yr (blue label being the most)
Black label, Chivas 12yr are slightly mroe economical.
Chivas regular, Cutty sark regular, red label are probably the cheepest you can get. I've had reb label now and then, not the others.