I hate both of my Deoxys, and my Jirachi just rots in my box(till I get around to training it to Level 100, but then it will just rot again =S), but I would never trade them away.
Deoxy's took me over 4 hours(And £10 in train fair) to get to the event. The trains getting out of Portsmouth were stopped, so not only did I miss seeing Serenity, I had to get a bus all the way to Chichister before getting to Croydon. 4 hours. But I meet a whole bunch of new friends(who I still keep in contact with at least one....=P),and was the furthest ive been away from home on my own. And Jirachi was gotten during the Eon ticket event were there was no sign of Jirachi for the Uk. Colo bonus disk, none of that channel crap.
And my Eon Pokemon, they got me the Eon Ticket event badge and T-Shirt! And I use them on Emerald.
So would I trade my legendary event Pokemon? The whole answer: Not even for a shiny version of each of them.