As the previous poster said, buffing your Allies is not necessary with your other cards, but protecting your key ones are.
Black is overall a bad ally color, though it does have one really good one: Bala Ged Thief. Red is pretty similar, with the only really good one being Kazuul Warlord.
The other three colors get more interesting.
White can get an amazingly fast start with the Hada Freeblade/Kazandu Blademaster combo, Kabira Evangel ensures free swings against most decks, and Ondu Cleric and Talus Paladin can keep your life up for a long time. Really, you can have pretty good success with mono-White Allies, so long as you protect them with things like Brave the Elements and Mark of Asylum.
Blue has the only flying Allies, in Umara Raptor and the one that give all Allies flying until end of turn. It also has Halimar Excavator (an amazing mill card), Seagate Loremaster (which will give you plenty of cards to draw) and Jwari Shapeshifter to ensure more copies of the Ally that your opponent is weakest against.
Green has a crazy mana engine in Haribaz Druid and a great buffing/token generator in Turntimber Ranger.
While my favorite Ally deck for fun is B/W built around Sanguine Bond, by far my most powerful is a very flexible G/U deck that looks something like:
4 Haribaz Druid
4 Halimar Excavator
4 Jwari Shapeshifter
4 Clone
4 Umara Raptor
2 Seagate Loremaster
2 Turntimber Ranger
2 Rite of Replication
4 Ponder
4 Divination
2 Kozilek, Butcher of Truth
1 Umalog, the Infinite Gyre
If they don't kill the Haribaz quickly, you can build Allies at lightning speed while milling them, then have the mana as early as turn 5 to kick Rite of Replication off Halimar for a minimum 180 card mill or off Umara Raptor for 5 7/7 fliers. The Legendary Eldrazi are there both for mill defense and as major beatsticks that are practical to get out quickly..