Lemme see...
I have...quite a lot in my 1,432 hours of playing... (in Pokemon Sapphire,I just checked, in Emerald I played for like...500+ only)
I'll name a few.
Shiny Bannete - Blue body, orange tail, eyes and mouth.
(Pokemon Sapphire)
Acquired on route 121 when it was a Shuppet.
Quite High Atk. and HP.
Shiny Heracross - Pink
(Pokemon Sapphire)
Went "omgwtfbbq!" when I saw this one in the Safari Zone.
High Atk., HP and Sp. Def.
Shiny Aggron - Blue body, white armor, red eyes.
(Pokemon Sapphire)
Got him in Dewford cave as an aron. :D
VERY high defence and attack.
Shiny Nosepass - ORANGE nose, very yellow.
(Pokemon Sapphire)
I was persistent in getting this guy xD saved right next to a rock, used rock smash, if it was a nosepass and not a shiny one, I would restart.
All I got in the end was (since he's level 100 now) HP 178 Sp.Atk 124 Atk 134 Sp. Def 208 Def 250 Speed 81..yeah
And lastly, I am most proud of my!!!
Shiny Weezing! - Bluish Green, the symbol is yellow.
(Pokemon Sapphire-- he's rare in this one :D)
Got him in Fiery Pass, my sister played and asked me why Koffing was a strange colour. And he was shiny.
HIGH Sp. Atk (300+!), Hp(250+!), AND Def(250+!). But the rest suffered . Speed 52 Sp. Def 61 Atk 38
I still got 13 more in Sapphire without cheats though. ._.