I'm a sucker for any black shiny (Rayquaza, Greninjam Charizaerd, etc.) but ever since hatching them, Shiny Bisharp, Aegislash, and Rotom have all grown on me a lot. Also, shiny Blacephalon. It's like a wxploding globe/disco ball/ice cream cake, and it's awesome.
These are my top 6. I think they look absolutely amazing. I'm also fond of shiny Virizion, Manectric, Palkia, Dialga, Giratina, Xerneas, and any blue shiny.
Spiritomb is always the first that comes to mind. I like Celebi too because of the mystery dungeon games.
My favorite shiny would have to be shiny flygon since it was the first shiny I ever got. I even got a regular flygon so I could compare the colors and I really do like the differences. Makes me think of making an acrobatics team (performers not the move) with one regular flygon and one shiny.
I actually just thought of another one. Shiny Chesnaught. I mean, why wasn't Chesnaught just normally colored that way? It looks so much better than the base colors. I really want one now. Might try breeding for one at some point.
Any blue/black shinies are cool in my book. Special mention to shiny Rayquaza, Charizard, and Haxorus because DRAGONS.
Yes, that one too. Did you know its shiny form used to be jade-green in Coliseum/XD? I thought that was cool too.
Yeah, I did actually. I had a shiny one in XD. I really enjoyed playing XD, and which is was considered canon since it was it's own region. Gen 4, I think.