Here we go with your list. It's in the format name / method:
Special medals
- Top Medalist: Get ALL of the other medals.
Adventure medals
- 100 Passerby: Pass 100 people in Tag Mode.
- Heavy Traffic: Pass 1,000 people in Tag Mode.
- Pass Power MAX: Use 100 Pass Powers.
- Sleeping Capture: Capture 10 Pokemon in the Entree Forest.
- Deep Sleep Capture: Capture 50 Pokemon in the Entree Forest.
- Sweet Dreamer: Capture 100 Pokemon in the Entree Forest.
- Great Adventurer: Get all of the other Adventure medals. (97)
Battle medals
- Subway Accelerator: Use the Battle Subway 10 times.
- Subway Top Gear: Use the Battle Subway 50 times.
- Runaway Express: Use the Battle Subway 100 times.
- Single Express: Beat the Subway Boss on the Single Line.
- Double Express: Beat the Subway Boss on the Double Line.
- Multi Express: Beat the Subway Boss on the Multi Line.
- Test Fan: Take 10 Battle tests in the Battle Institute.
- Test Enthusiast: Take 50 Battle tests in the Battle Institute.
- Exam Genius: Take 100 Battle tests in the Battle Institute.
- Battle Guru: Get all the other Battle medals. (55)
- BP Wealthy: Collect 100 BP.
- Johto Mightiest: Beat the Johto Leaders tournament.
- Hoenn Mightiest: Beat the Hoenn Leaders tournament.
- Sinnoh Mightiest: Beat the Sinnoh Leaders tournament.
- Mightiest Leader: Beat the World Leaders tournament.
- Worlds Mightiest: Beat the Champion Tournament.
- Rental Master: Win the Rental Master tournament.
- Mix Master: Min the Mix Master tournament.
- All Types Champ: Win all the Type Expert tournaments.
- 1,000 Wins: Beat 1,000 Trainers in the White Treehollow/Black Tower.
Entertainment medals
- Broad Friendship: Register 10 Friend Codes in the Pal Pad.
- Global Connection: Register 32 Friend Codes in the Pal Pad.
- Spin Trade Whiz: Play Spin Trade in the Union Room 10 times.
- Ferris Wheel Fan: Meet lots of people at the Rondez-View Ferris Wheel in Nimbasa City.
- 10 People Funfest: Play a Funfest Mission with 10+ people.
- 30 People Funfest: Play a Funfest mission with 30+ people.
- Scored 100: Score 100 points in a Funfest Mission.
- Scored 1,000: Score 1,000 points in a Funfest mission.
- Entertainment Master: Get all the Entertainment medals. (74)
Some tips:
Use Tag Mode lots; you'll eventually get the first two. After lots of time, of course. You seem to lack a lot of Medals from the Entralink, particularly the Entree Forest ones. For those just use Dream World lots and capture all the Pokemon in the forest. You have a lot of missing Medals from the Battle Subway; the first three should be able to be achieved while trying to get the others. Pretty much, just ride on many different trains and beat the Subway Bosses. While you're at it, you'll scoop up a lot of BP, hopefully enough to get the BP Wealthy medal. Hopefully you'll be able to get those Medals quickly by simply using the Battle Subway a lot. The Battle Institute medals are pretty simple - just keep taking the tests and get the Medal. The medals achieved at the PWT can be achieved by making sure you win every tournament; you will unlock and win the competitions required to get the medals by doing so. 1,000 Wins is pretty easy, but is very tedious and takes time. Just make sure you fight EVERY trainer in the White Treehollow/Black Tower, and you will eventually get the Medal. For the Pal Pad medals, just play online/with friends heaps and register everyone's Friend Code. Play a bit of Spin Trading with friends a bit too - to get the Spin Trade Whiz medal. The Ferris Wheel one is simple enough. Just ride on it every day and collect the medal. The Funfest mission ones will require lots of people. Once you have 30+, play a Funfest mission. While you're at it, score some points in the missions and get the four Funfest missions medals. Once you have everything, collect the Top Medalist Medal.
http://bulbapedia.bulbagarden.net/wiki/Medals#List_of_Medals