I transfered all my Master-rank winners from Ruby to Pearl, and I can't seem to win the master rank with them... But they've served me well, I think i beat one master rank contest in Pearl because I got a star on my trainer card for it.
Here are my winners:
Cool - Magnemite: Master Rank in Hoenn/ Great Rank in Shinnoh
Beauty - Milotic: Master Rank in Hoenn/ Ultra Rank in Shinnoh
Cute - Ludicolo: Master Rank in Hoenn and Shinnoh
Smart - Spinda: Master Rank in Hoenn/ Ultra Rank in Shinnoh
Tough - Banette: Master Rank in Hoenn/ Ultra Rank in Shinnoh
They've all served my so well, but I need to improve my own Coordinator Abilities to get the Master Ranks for the other 4 types in Shinnoh. They're a lot harder than the contests in Hoenn.
If you get a certain amount of ribbons on one pokemon in D/P you get into an exclusive club/building in the Battle Frontier, which I've gotten into. So that's why I did the ribbons this time around. And in Ruby, I was going for 100% completion, which is why i went for the master ranks on those 5 pokemon i just mentioned. I guess i love this game a little too much. haha.