Ugly: IAI Arava. Like a spreadeagle monkey humping a football.

If we're just talking major recent airliners, I'd say:
Best looking: 747, and in particular the older, non-stretched-upper-deck -300s as best proportioned. Although the -400s and stretched-upper-deck -300s aren't bad.

Ugliest: BAE-146
http://upload.wikimedia.org/wikipedi...00_Jonsson.jpg

I remember the first time I saw one (in the grey United livery, which didn't help it) and just thought "what the heck is that, and why did someone stick 4 engines on a regional jet?"

Most beautiful, has to be the Concorde, just ahead of the XB-70 Valkyrie

For ugliest, I will take the liberty of extending the timeframe back an additional 15 years, to include the Lancaster Bomber and the Consolidated B-24.

I love the simplicity of the MiG-17.

BAe-146 is the ugliest plane I have flown in. Looks like it was built from the scrap of 4 or 5 other planes.

Commercial? Concorde. The Beechcraft Starship is striking.

I don't actually think the BAE146 was ugly. I thought it was quite pretty IRL. Very balanced. Lovely to fly in. Ugly? Try the Breguet 763 Deux-Ponts. It's the plane that ate all the pies.

Military? The Mirage 2000 is just superb and glorious to see at speed. A late model Spitfire in flight is simply sublime.

Ugliest? Shorts really did have a knack for ugly, but they also did some amazingly important aircraft. The Russians had (have?) a knack for ugly military aircraft.

I've never seen those, but that is seriously fug.

The 146 had special handling characteristics and could approach a runway at a steeper glideslope that the standard 3 degree. I believe the engines had something to do with it.

^

Concorde; Blackbird; That"soomething 70 from Lockheed years ago; 747

I think it is one of the few types allowed to fly to LCY due to the glideslope as well as (maybe) noise restrictions. The engines were smaller which means quieter. Many carriers seem to be replacing them with E170s now though.

It makes sense; at the same time those characteristics aren't immediately obvious to a passenger, and it's (at best) a pretty weird looking plane.

Not nearly as ugly in pictures as the Breguet mentioned, or the Guppies, or the Dreamlifter, or a few other oversize-cargo carriers, but those I've only seen pictures of.

The Good: Connie
The Bad: F-16
The Ugly: Breguet 763 Deux-Ponts

any other votes for the Carvair?

The long sleek lines of the concorde, although it felt like sitting in the old first class of a 727 the plane was beautiful.

Lockheed Constellation is beautiful, but I also really like the 727-200.

I cannot stand the Airbus 319. That is one ugly bird.