A green that's available in act 1, and easy to ignore, is Melf's First Staff. It's a +1 weapon that allows you to cast Melf's Acid Arrow, which is okay. But the real killer is that it has a +1 bonus to Spell Save DC and spell attack rolls.
This makes it stronger than a lot of later staves that on first inpection look better. Stick it on Gale along with The Protecty Sparkswall robe which also adds +1 to Spell Save DC and a shield that also has the same buff. Job done. This is early-game kit you'll struggle to replace later on because the basic bonus is just so damn good.
There's a maul which would also be legendary if its main effect wasn't broken: Hamarhraft.
I read the description and thought it would be perfect for my very jumpy Karlach, but unfortunately, the advertised bonus doesn't trigger:
Shockwave: When the wearer jumps, they deal 1d4 Thunder damage in a 3m radius upon landing.
Gods, how I want this one to work. Massive hammers with awesome inpacts are my absolute favourite fantasy weapons. I adored hammer in MHW and I've been using hammer on my GW2 Warrior since launch.
I did recently get Corpsegrinder, which is okay, but its effect recharges on a short rest. If Hamarhaft was working properly, that would trigger on every jump.
That maul does work, but it's a passive you need to toggle on and off. It's a bit of a nuisance because if you're not careful about turning it off, you'll end up doing damage as you're just jumping around the world.