There are five different gadgets needed to get the "One Of Each" achievement. They are all unlocked automatically while playing through the story. The following gadgets have to be used in one combo, without ever losing the combo multiplier:

1. Batclaw Slam: Press LT + Y, X.
2. Explosive Gel: Press LT + X.
3. Concussion Detonator: Press LT + B.
4. Glue Grenade: Press RT(2).
5. Batarang: Press LT.