I know the average Joe doesn't even notice such mundane things, but I do. Show cars often have some pretty cool one-off treads, and some production tires also seem to put a value on looks in addition to performance.
For me, the first one I ever noticed and the best ever IMHO was the original Goodyear "Gatorback". The idea that a company could market a tire based on it's tread design, even going so far as to give it a catchy name, was pretty revolutionary back then. (Mid 80's) I even remember the first production car to wear them: Supra Turbo.
Gatorbacks are a good call. Also these:
jg
Gatorbacks came on my '86 Shelby GLHS. Great tires. Real gooey for the era. Went through several sets.
In reply to JG Pasterjak:
I was gonna say, the A008's the one other totally iconic tire from when I imprinted on such things.
The Gatorbacks blew my mind not only for looking cool, but IIRC looking more like a racing rain tire than anything else ever had at that point...
I was going to mention JG's. I think they were an inspiration for these:
GPS is close, but I have to go with this one. 
BF Goodridge G-force sports
lil brother of the T/A KDW
I believe the Sport at one time held the highest lateral G registered in testing of all tires in its tread class
I can't believe there's even a discussion here:
mtn
SuperDork
11/8/11 1:46 p.m.
From: http://grassrootsmotorsports.com/forum/grm/my-new-tire-story/40453/page1/
lol, well if we are going to go that route...
or maybe 
mndsm
SuperDork
11/8/11 1:48 p.m.
it's even got flames on it!
ST_ZX2
Reader
11/8/11 1:51 p.m.
Giugiaro Design penned the tread on the Vredestein Ultrac tire--meaning that a well-known design house, not computer-simulation modelling or real-world track experience created this...does 'look' cool, though...
I think it all depends on your age.
My favorite. Well, next to no tread.
mndsm
SuperDork
11/8/11 3:37 p.m.
I can't seem to find a pic of it, but the old T-bar mickey thompson cheaters always caught my eye. Probably because it was the first drag car I ever got close to. They were gorgeous. I remember touching the tread and being amazed at how soft they were.
Maxxis Ringworm - good to 110psi. Best BMX Tire Evar (for street anyway)
