This isn't an either/or type thing - all 3 tests are looking at totally different things. To repeat what MJ782 said, it all depends on your goals. Personally, I think autosomal is more useful in finding matches and researching ancestors who you can put a name and story to, as opposed to King so-and-so from the year 1300. Y-DNA is restricted to the male line, but it can trace your roots on that line way back to where normal genealogy isn't possible if that is of interest to you. It can also help sort out various family lines by joining a surname project.
I'm a firm believer in doing autosomal first on the oldest generation, i.e. great grandparents, grandparents, and down. In your case, that would be your two uncles who represent the oldest living generation in your family. The reason for this is the autosomal DNA inherited from any ancestor gets diluted each generation. Those uncles are going to have on average more remnants of your g-g-grandparents than you will. Also, they have the exact same ancestors as each of your parents, so their results will apply to you as well. In other words, your dad and his brother had the same parents, so there won't be any DNA in your uncle that isn't part of your heritage. Testing them should give you plenty of matches to trudge through.
After that, I would consider Y-DNA on the uncles. Note that if any of them have male offspring, testing them would yield pretty much the same results. As mentioned above, you can always do the cheaper test to get the results on file, and the upgrade later if there is a need.
And finally, I suggest testing yourself because each of your parents had a different DNA mix than their brothers, and some of that was passed to you.