My favourites are Kingdra, Ho-oh, Shaymin, Mew, Rayquaza and Ninetales I RNG so I'm lucky enough to have all of them; the Mew was in exchange for me RNGing a Shiny Legendary with a good IV spread for someone. I thought I was going to get a regular Mew so I feel quite lucky.
I'm on a break now but I sometimes hatch shiny pokemon for others and the most popular by far is Eevee followed by Charmander and strangely enough, Togepi. I cannot understand that as it looks so similar to the normal form. Maybe people just like the sparkles? Does anybody here like the Togepi/Togetic/Togekiss shiny form? I never see it mentioned in 'Favourite Shiny' threads and yet I'm asked to hatch it so often.
I'm really dissapointed in Shiny Houndoom. I love Houndoom but blue just doesn't cut it for me.
Volroc, I love Shiny Lunatone. When I get round to it I'll breed one and hatch it in Celestic Town and call it 'Lunage'. I have no idea what I could use it for. :(