
Originally Posted by
Blue Harvest
Gigalith is really cool. So much cooler than Golem. But why use this when Tyranitar, Terrakion, and even Aggron exist? Tyranitar and Terrakion go without saying as their secondary typing and vastly superior movepools are self explanatory. Aggron gets recoil-less Head Smash which hits with about 3% less power than Gigalith's Stone Edge, but without being reliant on specific weather. Aggron also has a much better movepool including Aqua Tail to 2HKO Hippowdon and Donphan with.
Outclassed somewhat in OU maybe, but you're right that Gigalith is still horribly overlooked. Too bad it has such low 25 base speed that it can't outrun defensive base 70s and lower, which is really nice so it could have beat Politoed, Skarmory, and Jellicent. It has trouble setting itself apart from the other offensive rocks but it seems sort of usable to some extent.
Also Shiny Gigalith is beautiful.

Aggron isn't OU, he's not even UU. He's LU.
That 4x weakness to Ground and Fighting really cripples him though.
Speaking of Aggron, try this set.

Aggron @ Life Orb
Jolly - Rock Head
244 Attack, 82 HP, 184 Speed
-Rock Polish / Autotomize
-Head Smash
-Earthquake
-Superpower / Brick Break/ Aqua Tail
Rock Polish lets him hit 400 Speed at +2, where he can then begin to sweep. Head Smash is a devastating STAB attack, with Earthquake to round off the coverage. Superpower gives more coverage, but lowers his stats, so Brick Break can be used as a weaker option that also smashes Screens. Aqua Tail is a third option for Hippowdon and Donphan and the like. HP EVs give him 301 HP, enough to survive a lot. The rest go into Attack.