I'd recommend exchange plan dieting, because some balance is already built in. But you still have to know what you mean by complete (or balanced), because even dietitians don't all agree on the best diet (or if there even is one).
I like exchange plans, because they're easy to adapt to almost any style of eating - so when my idea of "balance" changes, so can my diet. I have done exchange plan "versions" of South Beach, Atkins, Primal Blueprint, Volumetrics, Gary Taubes Good Calories, Bad Calories....
Exchange plans are almost as flexible as calorie counting (which is another good choice - but you have to understand and create the balance yourself).
The Shoestring Meals forum has many great tips, recipes, and techniques.
There are also a lot of great books (check out amazon.com by searching healthy eating on a budget - and when you look at the books' pages look at the other books recommended on that page).