The Sinnoh Champion: Sinnoh Champion Ribbon - Enter the Hall of Fame
The Once Well-Trained: Effort Ribbon - Max out EVs
The Great Friend: Best Friends Ribbon - Max Friendship
The Gorgeous: Gorgeous Ribbon - Buy for $10,000 in Resort Area
The Royal: Royal Ribbon - Buy for $100,000 in Resort Area
The Gorgeous Royal: Gorgeous Royal Ribbon - Buy for 999,999 in Resort Area
The Strutter: Footprint Ribbon - Gain 30 levels or enough Friendship
The Shining Star: Contest Star Ribbon - Achieve all five Master Rank Contests
The Twinkling Star: Twinkling Star Ribbon - Be Star of the Show in every Contest Rank
The Tower Master: Tower Master Ribbon - Defeat Master Class Palmer
The Former Star: Coolness Master Ribbon - Embody Coolness in a Contest
The Vintage Beauty: Beauty Master Ribbon - Embody Beauty in a Contest
The Former Idol: Cuteness Master Ribbon - Embody Cuteness in a Contest
The Historic Genius: Cleverness Master Ribbon - Embody Cleverness in a Contest
The Formerly Buff: Toughness Master Ribbon - Embody Toughness in a Contest
The Once Vigilant: Alert Ribbon - Talk to Julia in Sunyshore City on Monday
The Once Cowardly: Shock Ribbon - Talk to Julia in Sunyshore City on Tuesday
The Once Shaken: Downcast Ribbon - Talk to Julia in Sunyshore City on Wednesday
The Once Imperfect: Careless Ribbon - Talk to Julia in Sunyshore City on Thursday
The Once Well-Rested: Relax Ribbon - Talk to Julia in Sunyshore City on Friday
The Once Sleepy: Snooze Ribbon - Talk to Julia in Sunyshore City on Saturday
The Once Cheery: Smile Ribbon - Talk to Julia in Sunyshore City on Sunday
List of Ribbons (Bulbapedia)