Among the beautiful jets there's just too many of them to enlist.
The Hawker Hunter, Northrop F-5, Lockheed Startfighter, BAC TSR.2, Lockheed SR-71, Convair F-106, North American A-5 Vigilante... this list could become pretty endless.
Sleek lines, like found in many 50-70 designs, make most of them look pretty in a way.
Talking about planes that "look somewhat wrong, yet effective" like the Fairey Barracuda, I'd also like to throw in the Blackburn B-54:
Best regards - Mike