Aizen via the Orb Of Disruption/Hogyoku (Bleach, has such control of it that taking it from him does not weaken him)
Bakutou users (Bleach)
X-cution members (Bleach, via their respective Fullbring weapon)
Juggernaut (Marvel Comics) Only had to touch the Gem of Cytorrak to initially recieve his powers, not needed afterwards.
All Green Lanterns (DC Comics) Powers derived from rings that must occasionally be recharged by the Green Battery.
Various other Lantern Corps (DC comics) each have rings similar to the Green lanterns that provide various themed abilities.
Amazo (DC Comics); via copying Green Lantern's Power Ring.
Kratos (God of War universe) via various weapons and accessories (most notably the Blades of Chaos/Athena/Exile). It should be noted that Kratos is also granted innate, magical powers over the course of his storyline by various gods and other entities.
Shocker (Marvel Comics), via his gauntlets
Mysterio (Marvel Comics), via his tech and special effects
Dr. Octopus (Marvel Comics), via his tentacles
Green Goblin (Marvel Comics), via his tech.
Falcon (Marvel) flight via his wing harness
Iron Man, War Machine, Iron Monger, Crimson Dynamo, Titanium Man, & Box via their armor (Marvel)
Captain America (Marvel) via the Super Soldier Serum
Black Cat (Spider-Man: The Animated Series) via Super Soldier Serum
Star Girl (DC Comics)
Star Man (DC Comics) (2nd)
Ben Tennyson (Ben 10) via the Omnitrix
Thor (Marvel) via Mjolnir. It should be noted that Thor also possesses innate, godlike powers that his hammer augments. In some continuities his hammer provides additional powers rather than augmenting his innate powers.
Captain Marvel (Marvel) via Kree Nega-Bands
Rick Taylor (SplatterHouse) via the Terror Mask
All Power Rangers (Power Rangers) via their morphers
All Sentai Rangers (Super Sentai) via their henshin (transformation) devices
Rhino, Scorpion, Shocker, Dr. Octopus, Venom, Carnage, and Vulture (Spider-Man, Marvel) via their costumes
All Excorsists (D. Gray-man) via their Innocence)
Thanos, then Adam Warlock (Marvel) via the Infinity Gauntlet. It should be noted that each of these characters also possessed innate powers, and that the Infinity Gauntlet provided additional powers.