This discussion may contain spoilers!
Mad props to Holyxion for posting his lists - I just figured it'd be convenient to have a thread that lists everything in its first post. Thanks to Jake from Telltale and DangerZone for the last Expression of Affection.
I have personally confirmed each of the items listed here to be accurate.
Update: The official Telltale Awesomeness guide for Baddest of the Bands has been posted here.
1. Larry - Click on the Luxa Lounger in the Strong's living room
2. Perry - Use the Microphone outside the Strong's house
3. Gary - Use the Black Metal Detector outside Marzipan's house
4. Mary - Click on the Dead Fish in the pond (after it has been bleached)
1. Two-O-Duo - Use the Metal Detector near Bub's Conces5ion Stand
2. Cool Tapes - Click on the left locker at the Track
3. PomStar - Use the Microphone at Club Technochocolate
4. D.O.I. - Use the Metal Detector at the D.O.I. stage
Limozeen: Hot Babelian Odyssey Manual Pages: (These are always awarded in the same order.)
1. Use the light switch in Strong Bad's Lappy room
2. Use the Microphone at the Cool Tapes stage
3. Use the Metal Detector at the Two-O-Duo stage
4. Use the "Doin' the Wigglie" record at Club Technochocolate in Extended Play
1. ʎɥsoןs shirt - Use the Microphone in the Strong's laundry room
2. Leopard Print Pants - Click on the couch in the Strong's basement
3. Hollywood Boulevards - Use the Metal Detector near the picket fence in The Field
4. Headband - Use the Microphone near the brick wall in The Field
Strong Bad Abuse
1. Click the Lappy's Plug
2. Click the microwave in the Strong's kitchen
3. Use the fake sword on Marzipan
4. Talk to Strong Sad at the Battle of the Bands
5. Use the bleach directly on the pond at the Battle of the Bands
1. Give Strong Mad an Entry Form
2. Give The Cheat an Entry Form
3. Give The Cheat an Entry Form a second time
4. Use the Boom Box option on Coach Z outside Marzipan's
5. Use the "Slide to the Right" record on the Technochocolate turntable in Extended Play
6. Use the "Doin' the Wigglie" record on the turntable twice in Extended Play
7. Talk to Strong Sad in Extended Play
Expressions of Affection
1. Talk to Strong Sad about the bats twice (at the start of the game)
2. Talk to Bubs about the Funmachine
3. Talk to Coach Z about Marzipan twice (at the Track)
4. Have Marzipan make out a glossy to Strong Bad
5. Have Marzipan make out a glossy to Coach Z
6. Have Coach Z recite poetry for Marzipan (outside her house)
7. Talk to the Limozeen standee about Two-O-Duo (before sabotaging them)
8. Talk to the Drive-Thru Whale at the PomStar concert twice (before sabotaging them, and before inserting the coat hanger, or while the hangar is pointed away from anything)
9. After you have sabotaged PomStar and Two-o-Duo, and given both the whale and pond photos to Marzipan, turn your hint level to "High" (in Options) and click randomly around the Two-o-Duo stage until Strong bad mutters the hint "The Teen Girl Squad would love this..."
10. Talk to Coach Z in Extended Play
Limozeen: Hot Babelian Odyssey
Score at least 45,000 points.
Bonus Costume Item for attaining 100% Awesomeness
Mysterious Hidden Shirt
Yellow creature shirt - As with the previous two episodes, walking underneath the doorway of the photo booth will cause Strong Bad to automatically wear a hidden shirt. Get beneath the booth floor by walking off the right edge three times while not wearing any costume items.