Rolling Thunder out of the ammo machine outside Zed's in Sanctuary. Neogenator in the Zed's vendor outside Marcus's in Sanctuary.
Slagga in chests at Terramorphous Peak and the elevator area of Sawtooth Cauldron. B!tch in the chest at the end of the "Too Close for Missiles" area in the Dust. Pandemic in a chest in the Drydocks area of Three Horns Divide. Striker and Baby Maker in the chests in Marcus' Storeroom after Where Angels Fear to Tread part 2.
Got a lot of use out of that Pandemic -- Three Horns Divide is mostly level 7, but there are a few chests that are level 14, the Drydock ones among them. So it stayed relevant, and was particularly nice to have when storming through A Dam Fine Rescue.