I'll be honest...
Trophies are nice for the photos and a little reward, but once we get home they usually go in a box. I've got several boxes of them somewhere. If that tells you how important they are after the fact, that I don't even know where they are...
The bulk of the trophies I've seen have been the plastic variety that is pretty common. Wood plaques that hang on the wall are better, but to be honest most of those are in boxes somewhere too...
The best ones I think are the certificates that can be framed, or better they can be inserted in clear holders and placed in a 3 ring binder. One of the better ideas I have seen was a long time ago the Topeka club printed up the certificates, and had a spot in the center for a polaroid of the pilot and plane. It probably was more work, but at least it's easy to tell if the trophy was mine, or dads, and I know what was flown, what the weather was like, etc...
Something like a dash plaque would be neat too, small brass plate with the contest info, date, event, and placing... Cause who has room for a bunch of trophies? The guys that usually take them home are always the same crowd, its unlikely anyone will have just one trophy that a big plastic and gold trophy will be displayed with pride.