I'm with markem, life is too short for cheap scotch but if I had to choose a "bargin" scotch it would be Smokehead for about $60 locally (that's as cheap as malt gets in BC

) or significantly less if I pop over to Alberta or WA. My "cheap" scotch used to be Ardbeg 10 and Laphroaig 10 before demand pushed the former to $100/bottle and discontinued the latter in Canada.
In terms of favourite regardless of price?
Toss up between the Laphroiag 15yr (Prince Charles' favourite whisky, awarded his Royal Warrant to the distillery for it), Bowmore 17yr (now re-released as an 18yr) the Ardbeg Airigh Nam Beist, Lagavulin 16 and Longrow 14.
The picture's a little out of date now, but this is my whisky cabinet. I tend to buy in doubles and triples so most of the tubes behind the bottles have an unopened bottle in them as well. My friends refer to them as "shark's teeth" bottles