With the changes coming to magic once Shards block and M10 rotate out of standard, I've decided to post my version of the Green Red Valakut Combo deck that uses no cards that are rotating out any time soon.
Card Explanations (in order of mana cost):
Valakut, the Molten Pinnacle-Duh, it's the way this deck wins.
Evolving Wilds-Fetches forests early game, and provides mountains at instant speed late-game. Post sideboard, it fetches plains for Terra Eternal in case I need it.
Terramorphic Expance-functionally the same as evolving wilds.
Expedition Map-It fetches Valakuts. Having two Valakuts and 5 mountains primed and ready on turn 4 is a very powerful thing.
LIghtning Bolt-If you run red, you should run Lightning Bolt. This card singlehandedly provides early creature control that can be invaluable against decks that use lots of creatures, and has won me many games.
Dragonmaster Outcast-Should be fairly obvious, it makes dragons. Dragon Beats FTW.
Khalni Heart Expedition-This card what makes the deck run. Play him turn two, turn three play a land and a harrow, crack this, suddenly you have more mana than you can use. This card should go in any green deck (even if green is just a splash color), but it's expecially good here.
Cultivate-Super Secret tech with oracle of mul daya. Also a good topdeck if you have no lands in hand. Just good in general, and a nice replacement for rampant growth, which is rotating out with M10.
Harrow-It's cheap, efficient, and puts two lands into play. Very good. The only downside is if it gets countered you still have to sacrifice a land.
Oracle of Mul Daya- Playing an extra land each turn is never a bad thing. Playing an extra land each turn from the top of your deck and improving your draws is even better.
Kazuul, Tarant of the Cliffs-This card gets looked at with some skepticism, but he is actually incredibly useful. He's usually a turn 4 play in this deck, and he really provides an extra edge against aggro decks that would usually beat you to a pulp before you can get your Valakuts online. I've won games with him where my opponent destroyed all my Valakuts! And at 5/4, he's not a bad beater either. I was running Kazuul over Siege-gang before the rotation, and now with the rotation its even more of an excuse to run him. It's a three-of because he's legendary.
Comet Storm-A big, red, variable cost, non-creature finisher? I find myself with 9 mana, why not spend it on this awesome card? It's a three-of because I usually only want to draw it once or twice per game.
Sideboard Cards:
Terra Eternal-When I face some decks running Tectonic Edge, goblin ruinblaster, or something similar, I sideboard this in. It's why I maindeck one plains.
Goblin Ruinblaster-good in the mirror match and against decks that run lots of nonbasics.
Pyroclasm-I switch this for scute mob against weenie decks.
Mitotic Slime-Against creatureless decks or decks with few creatures, this is a better choice than Kazuul.
Finally, If you have some Primeval Titans, feel free to use them. They are incredibly useful and improve the deck tenfold, I just don't want to spend $160+ on a playset (not even kidding).