Couch312

http://www.mtgvault.com/couch312/decks/spellflinging-challenge/
It's opposite day, let's see just how few creatures you can use.

Nobody recommends blue control because it's boring, sorry to say. Yes, it wins, but usually the only players that play it are the players that have been around for a while and are willing to grind the game out. Same with death and taxes. Easy to build, easy to play, just really grindy and difficult to like.
Same with discard decks.
Both decks win games, but you have to be willing to grind, and quite frankly have to be okay with minimal interaction.

I like the whole limited thing in casual, because if you don't you end up with things like Protean-Flash which is strictly a casual deck, since the full list is banned in every format.
http://www.mtgvault.com/couch312/decks/turn-0-win/

Anytime man, I'm all for designing your own deck. I do know that the deck design I run is kinda lame, but it wins. The few times I lose I'm never crushed, it's always by the skin of their teeth, ya know?
From a deck builder's standpoint, you want to create your own deck, from a competitive standpoint, you see a lot of the same decks because they consistently win. I don't think I've ever not made it to the top 8 when I play affinity.
If etched is more of win con you should put some equipment in there to make him nice and fat. I'm a fan of Deathrender, or any of the 3 drop swords.

I'm unsure of what is going on with this deck. It says competitive in the tags, yet this says legacy legal and you're running serum visions over brainstorm? 1 Serum vision costs more than the playset of Brainstorms. Same with Ponder, and both are strictly better than Serum Visions.
From what I'm looking at I'd say your only win condition is the Colossus. If so I'd suggest running 4 since exile effects are huge in white. I'd also run some counterspells like Spellpierce, Daze or, if you have any, force of will.
Have you thought about using the Urza land since you have a lot of high cost artifacts, and while using Master Transmuter is a way to do it, she is susceptible to removal.
Artifact Affinity is an entirely different story.
http://www.mtgvault.com/couch312/decks/artifacts-and-stuff/
The goal of an artifact deck in legacy is usually to swing fast and swing hard. Having an opponent at 3-7 health on turn 3 is not uncommon.
All in all I don't see any win conditions for this deck other than Darksteel Colossus. I mean, you have 1 etched champion, but he's not going to do much good without equipment.
I hope that you can get this thing going strong, I like artifact decks, the link I provided is one of two go to decks for an event I actually want to win.

Sorry, didn't see that.

http://www.mtgvault.com/couch312/decks/tribal-challenge-dragons/
Slowest deck ever made, but there be dragons.

http://www.mtgvault.com/couch312/decks/tribal-challenge-foxy-foxy/

http://www.mtgvault.com/couch312/decks/tribal-challenge-elephants/

The elemental deck is just fun. Nobody likes it when I harbinger into nova chaser, because nova chaser dies easily, but swings for 10 with trample, and when it dies harbinger drops back on the field and I fetch another chaser. There are no easy answers unless you're running a lot of counterspells.

That's because Faeries, like elves, has a really cheap core, it's the things like bitterblossoms, or gaea's cradle that hurt your wallet.

http://www.mtgvault.com/couch312/decks/tribal-elemental/
Old tribal elemental deck.

http://www.mtgvault.com/couch312/decks/tribal-challenge-faerie-swarm/
For the swarm.

http://www.mtgvault.com/couch312/decks/tribal-challenge-treefolk/
Killer trees man.

I'm not sure how tight your budget is, but here is a list. If you could I'd play the full set of Banishing light and Master of the Feast over Disciple and Herald. I can't believe bad Oblivion Ring is over 2 dollars. Basically it's constellation abuse with Grim guardian. You play mono black devotion aggro with master and herald with lots of hand hate to get rid of their answers. Skybind will be sure to give you multiple constellation triggers in a turn and whip of erebos will give you gray merchant recursion.
4x Brain Maggot
4x Grim Guardian
2x Herald of Torment
2x Master of the Feast
4x Underworld Coinsmith
2x Skybind
2x Banishing Light
4x Gray Merchant of Asphodel
2x Disciple of Phenax
4x Silence the Believers
2x Whip of Erebos
4x Duress

The question is if the player has already had the god on the field as an enchantment and you reach devotion while they're in the battlefield do they have summoning sickness. the answer no. as long as you've controlled it for one of your untap steps you can swing with it as the same turn you reach devotion.

Sideboard? Maybe? Encroach doesn't do much to elves or goblins, there is even an almost mono color death and taxes deck starting to see play. Getting rid of their immediate threats with inquisition or thoughtseize is strictly better.

http://www.mtgvault.com/couch312/decks/budget-whats-mine-is-yours/
Didn't see that coming didjya?

Build deck around turn 1 obliterator, then turn 1 obliterator in a game, try not to laugh, laugh a lot.
Urborg turns everything into swamps in addition to whatever else they do, so you now have two black sources on turn two to play hexmage, sac it to remove counters from dark depths and have a 20/20 flying, indestructible token.

http://www.mtgvault.com/couch312/decks/some-sort-of-mill/
Do like to draw cards? Me too! Maybe. I have no idea what I did with this.