I think there are a lot of us who don't fit the "Johnny Doo Rag" or "Three Weeker (Sturgis, Daytona, and 5 nights at Quaker Steak)" stereotype- we simply have liked the motorcycles for a long time.
There's a lot to be said for HDs, IMO. Loads of available parts (that, contrary to popular opinion, are typically less expensive than for other motorcycles due to the fact that one part fits so many bikes), ease of maintenance (belt drive, self-adjusting valves, air-cooled, spin-on oil filter), plenty of usable power that can be upgraded- I think my buddy ratt from cycleworld put it best: "Harleys are the most fun you can have riding the speed limit". Not to say that they cannot exceed that limit- but you get the idea. So many people have bikes capable of riding balls to the wall- but the realities of their skill, or local law enforcement make it more likely to see them cruising down the same roads as a Harley rider, at similar speeds.
I had a Superglide (1997 FXD), and loved it. I toured on it, took it on road, even on some "off-road" fire trails- it was a blast. The summer after I bought it (1998) I had put about 12k miles on it, and some guy offered me far more than I paid for it- so it went away... ...but it remains a favorite of the bikes I've owned.
As for how I obtained more power out of the Road King- Andrews TW26 gear-drive cams, a high-flow air cleaner, and a set of Samson rolled-thunder slip-ons. I could have gotten more torque with a Thunderheader, but I wanted the traditional look, and I wanted the bike to be a bit less loud.
Harleys are not the "best bikes in the world", but if you are into 'em, they are the best at being Harley.