Damnit, just the time for my 'puter to go kaput and not let me access the Casual Decks section... Someone goes and posts about Greater Good!
Gizmo, stay ducked please... [me] starts throwing things... [/me]
Duel, you're gonna get yourself killed with that attitude! I'm gonna mill you to hell and gone!
J/K
Fire Slinger, I don't actually Greater Good to deck people, that's just the engine the deck runs off. The kill is provided by Alter of Dementia, working upon the same lines as Greater Good.
I'll give you an approximate decklist (believe it or not, I never wrote down a decklist for that version!).
4 Llanowar
4 Priest of Titania
4 Fyndhorn Elves
4 Seeker of Skybreak
3 Rofellos
1 Vitalize
1 Soldevi Digger
3 Alter of Dementia
4 Greater Good
1 Worldly Tutor
4 Endless Wurm
3 Weatherseed Treefolk
4 Rancor
2 Gaea's Cradle
1 Treetop Village
17 Forest
That's one of the more recent Extended versions (note I haven't considered MM block in that list yet). It's the pure combo version (there's about 30 versions), designed very simply to strike hard and fast with Greater Good. The idea is simple, Elves provide mana, then drop a Greater Good and a fatty. Draw a pile of cards (and probably a new fatty). Rancor fatties for more card. Draw draw draw. Play more elves, make more mana with Priest and Seekers. Empty library. Play Alter. Play Digger. Play Vitalize. Use Digger to put 5 cards back on top of your library, including Vitalize. Play Weatherseed. Do not Rancor it. Sac it to Greater Good. Draw deck, play Vitalize. Rinse, lather, repeat.
Make tons of mana. Win.
It looks like a shaky combo, but the deck plays suprisingly smoothly, once you get the hang of what you should be doing at any given time (i.e., sack the Wurm or beatdown?). The deck wins any number of ways, dropping a Wurm and Pissing It Off wins against anything that isn't Black. A ton of Elves beats Blue. The combo beats everything. The card advantage from Greater Good stops White and Blue. The Alter hurts combo decks. The Weatherseeds kill Black. You get the idea.
Variety.
I've written things before discussing every single aspect of this deck, the interactions of every card, and theorizing on how to play it best in dozens of situations.
I'm not gonna type all that here, though. It'll take years...
Anyways, that pretty much covers _that_ version. There are hundreds of varients, if you want to see those, go ahead and ask... I'll type a few out for ya'.
GREATER GOOD IS THE BEST CARD EVER PRINTED!!!!!!!