I think the best non-fancy deck is just RW beat down. Like 5-6 2 drops, 4-5 3s and a couple finishers.
Grasp of the Hieromancer is actually quite good if you are on the beat down. The red aggro auras are a little more gambly. In both cases I probably take them out vs. blue.
W and R are the best colors, but not by a whole lot, and all color combinations are playable if they are open. U has some really good cards (especially uncommons) but is super shallow. G is deep, there are a lot of playable commons... but I have seen many (and drafted a few!) green decks that don't have enough 2s and they never get to play Rhox Maulers or 6/6 spiders and just die.
Black is a little shallow but solid.
I don't think any of the synergy decks are worth reaching for. The only one I have seen do well consistantly is Elves, and that's mostly because there are a whole lot of green (and a couple black) elves that are just solid aggro cards.
RU artifacts would be good except all the good R and U artifact cards go in any deck -- so it comes down to
Chief of the Foundry (drafting it and drawing it at the right time.
The best uncommons golds I think are UW with fliers (because hey, fliers are good in limited), and RW (2/2 double striker) because even if someone is drafting all the red and white removal, you can pick 2 drops, combat tricks and enchantments and still kill them. You can even play 1 drops and
war horn. Note that these aren't real synergy builds (except maybe warhorn.dec)
RB sacrifice is something of a "thing" but really it's just "Nantuko Husk is a really good magic card".