Well, I've only gone out of my way to get a shiny (Ponyta) once, and that was only because it was in Diamond, and Diamond has that.. >>; Gah. Tip of my tongue. Poke-tracker-thingy. Otherwise, I've had the unfortunate luck to run into a shiny Spinda and Makuhita on Sapphire with no Pokeballs.
Anywho, I can see the attraction to shiny Pokemon. To someone like me, who absolutely hates possessing/doing something so unspectacular that it can be aquired/done by anyone (in Pokemon terms, having regular Pokemon. In real life, something like reading the same manga series as someone else.), shiny Pokemon are a special treat because it makes my Pokemon different-- even if the difference is totally insignificant. Also, as a roleplayer, I tend to unconciously give my Pokemon defining traits and a look of their own. Having a shiny Pokemon just personifies whatever I draw up in my imagination all the better.
Then, they can be a challenge for collectors to get their hands on. People who enjoy flaunting their Pokemon have all the more to show off if the Pokemon is shiny.
In my opinion, shinies are coolio 'cuz they differentiate themselves from regular Pokemon. .o.
Tha's just my two cents, though.
Edit - POKERADAR. That's it. :o
