Who’s on top of the Forbes’ Hollywood’s Best Actors for the Buck? Of course it’s our man Shia LaBeouf! Forbes count down the top 10 actors who made huge box office hits, and it is Shia’s second year in a row.

LOS ANGELES — Earning $20 million upfront for a movie is so 2007. These days studios are squeezing every cent they can out of actors, and that means many stars only earn the big bucks after the studio gets back its money.

In these frugal times it’s useful to look at which actors earn studios the most for their money. Pay someone $10 million to star in your big summer blockbuster and what can you expect for your investment? If you hire Shia LaBeouf, expect a lot. For the second year in a row, he tops our list of Hollywood’s Best Actors for the Buck.

When LaBeouf starred in the first Transformers movie in 2007, Viacom’s ( VIA – news – people ) Paramount Studio was able to pay him under $5 million. It had to bump that up considerably for the second film (which earned $833 million in 2009), but LaBeouf still isn’t earning $20 million upfront to star in a picture.

As a result, he offers a great return on investment. For every $1 studios spend on the 24-year-old actor his films return an average $81 of profit. For our list this year LaBeouf also benefits from the fourth Indiana Jones film, which earned $790 million in 2008. George Lucas, Steven Spielberg and Harrison Ford split the bulk of the profits from that movie leaving LaBeouf as a profitable costar.

As the actor’s fame (and box-office earnings) increase he’ll be able to demand more for each film which will hurt his return on investment number unless the films are gigantic blockbusters. That could be the case with the next Transformers movie. LaBeouf was able to ask for more money upfront but because the movie is being filmed in 3-D, it should earn even more than Transformers 2.

And yes, we all expect that Shia will make another hit from the third Transformers movie! =D