>>96516436
That's pretty broad. I have four Gruul decks at the moment and they're dictated by the commander.
>Roxanne
Drop a bunch of meteors and treasures on the field, clone Roxanne a bunch, kill with a giant X spell or infinite combat through Reaver Cleaver and Aggravated Assault.
>Anzrag
Force blocks and give him indestructible or first strike and get as many combats as the opponent has blockers.
>Tannuk
Landfall burn. Kind of boring.
>Bello
Beeg artifacts and enchantments. Play a bunch of fogs to prevent dying due to your blockers disappearing every turn.

I love green and I like the crossover between the colors but the red stuff is mainly there for damage multipliers, burn finishers as your mana dump, and haste enablers. Green has the draw, the ramp, the big creatures, the removal, and the protection. But god are the Gruul pip combo cards fun. Xenagos and Cactusfolk Sureshot are two of my favorite cards in the whole game. I've been considering spinning Xenagos off into his own deck since I play him in so much already.