The Vickers VC-10 looked nice but few airlines bought it.
The BAe 146 is ugly but I liked it as a passenger.
If we're looking at beauty, I like the 767-300ER and the A340-300. Among obsolete jets, the Concorde and the L1011-1 looked nice. The 737-200 Combi doesn't look bad either but the newer 737's don't look as nice (tail is uglier and engines too big).