"the beautiful garden"
Пре at the start of an adjective is an intensifier, in at least some cases. Красный used to mean beautiful, but then the meaning changed so that красивый meant beautiful and красный became red, but прекрасный remained unchanged (incidentally, this is why we now have Red Square instead of Beautiful Square).
By the way, it's useful to know the old meaning of красный because it survives in a few cases, e.g. красный угол, the corner where the icons are kept, and in poetry, красное солнце and various forms thereof.
Right. To describe someone's good looks, красивый is the safest word.
Прекра́сный actually has two meanings: 1) beautiful 2) excellent, great
and I have a feeling that it generally takes the second one when used to describe a person.
It does mean 'beautiful' in emphatic sentences (Как она прекра́сна! – How beautiful she is!) or in comparisons (Он прекра́сен, как гре́ческий бог. – He is as beautiful as a Greek god.) or in obvious collocations where another meaning is unlikely (прекра́сные глаза́ – beautiful eyes), but not in sentences like Он(а) прекра́сный челове́к – (S)he is a great (wonderful, fine, lovely) person. Hm, it looks like прекра́сный is 'beautiful' in predicative position and 'great' in attributive more often than not.
Otherwise, just assume whatever meaning is more logical – прекрасная пого́да is 'fine weather', прекрасный приме́р is 'an excellent example', but прекрасный гобеле́н is 'a beautiful tapestry'.
Hmm, maybe just a little bit. :) "Он прекрасен" is stronger than simply "он красивый" and means that he is just perfect, but it’s certainly not offensive. I think -Maxim- was trying to tell that it would be strange for a man to call another man like that (well, it depends :P).
Another word for 'good-looking' is симпати́чный. This one is somewhat weaker than красивый and means that someone is just nice, pretty and pleasant to look at. It can be equally used for men and women, especially young ones.
Thank you Gwenci, for another beautifully clear explanation ;)
I am getting the impression from this thread that прекра́сный resembles beautiful in English in that if you apply it to a man you are complimenting his appearance, but at the cost of slightly insulting his masculinity, by implying an androgynous quality to his appearance. Is this correct?