I'd love to hear about anyone's favorite single malts or bourbons. Yes, the two are very different in many ways but likely often appreciated by the same people. Here are my current favorites. I'm very partial to heavily peated Single Malts, especially from Islay:

Single Malts:
Lagavulin - 16yr (pure heaven, the complexity combined with the heavy peat)
Caol Ila (I've only had several independent bottlings, but I've loved them all - there's something about the peaty, briny touch of olive combination)
Ardbeg - 17 yr (again, complexity with the heavy peat is hard to beat)
Highland Park - 12 yr
Talisker - 10 yr
Laphroaig - 10 yr
Favorite non-island malts are Cragganmore, Ben Nevis and Macallan

Bourbons:
Evan Williams Single Barrel Vintage
Knob Creek
Elijah Craig - 12 yr (great quality at a cheaper price)
Wild Turkey Rare Breed
Woodford Reserve

I don't drink Bourbon, but some of my favorite Scotches are:

Oban 12yr. (Western Highlands)
Cragganmore 12yr. (Speyside)
Highland Park 12yr. (Orkney)
Macallan 25yr. (Speyside) I don't actually own this, but my dad does and it's phenomenal. I like the 12yr. as well.
Lagavulin 16yr. (Islay)
Laphroaig 10yr. (Islay)
Bunnahabhain 12yr. (Islay)
An Cnoc aka. Knockdhu 12yr. (Islay)
As you can see, I am a fan of the Islay malts. I also really like most Speysides.

Mmm Oban!