7. Cute Loot Achievement/Trophy
To unlock this Achievement/Trophy, you'll want to find and kill a rare "Chubby" monster, whose death will also net you some special loot.
To find one, fast travel to the Highlands and head through the tunnel on your left. If you're lucky, Chubby will be hanging around near Blake Bridge, but he only comes out infrequently and at night, so if he hasn't spawned, try again after completing a few missions.
8. Unlimited Eridium
Eridium is great. Not only does it augment elemental powers, it's also used as a currency to buy upgrades on the black market. If you're feeling like a bit of a cheat and want an infinite supply, head to Three Horns valley and go north to the hideout where you fight Bad Maw. Kill him and pick up the Eridium he drops. Go into the Bloodshot Stronghold, save and then quit. Go back to Three Horns Valley and exterminate Bad Maw once again. Repeat until you get bored, or Gearbox patch the game.
9. Obtain the Nova Shield and get easy Badass Points
We're irrationally fond of Nova damage, and it just so happens that there's a Level 9 shield that gives you all the Nova damage you could ever want. Simply complete Lilith's Firehawk missions (which begin in Sanctuary) and you get a shield that blasts out a fiery shockwave when depleted. The great thing is that the shockwave often ignites enemies, so if you get knocked down while they're flailing around, there's a good chance that they'll expire in time to trigger a second wind.
The other great thing about this shield is that, with enemies being incinerated left right and centre, your "Cowering Inferno" challenge will be maxed out in no time.