I know this is an old question, but it gets viewed a lot so I thought I would update with the fact that this experiment was actually done on the first Mythbusters Breaking Bad special, episode 206. There is a description of the results of the episode inside that link.
Is it actually possible to dispose of a body with hydrofluoric acid?
To summarize from the Mythbusters episode, they tested out hydrofluoric acid on various small scale materials (to simulate the bathtub) as well as pig parts (the body) and found that $\ce{HF}$ certainly deteriorates some of the materials, but not at anything close to the same speed as in the show. It is even less successful at decomposing the actual flesh than the materials. One way of viewing this is to remind yourself that the ability of $\ce{HF}$ to eat through materials actually has more to do with fluorine's reactivity than with the ability to give a hydrogen atom (it is classified as a weak acid), thus it's reasonable that $\ce{HF}$ might be better at disrupting the structural integrity of metals/polymers than acidically eating through flesh.
See this question for details about its reactivity with glass. Mythbusters notes that a fiberglass bathtub actually would've behaved similarly to what we see in Breaking Bad, but over a much longer timescale.
So it's perhaps feasible to dispose of a body with $\ce{HF}$ given a very large amount of time, but it's not possible in the timescale presented in the show.
If hydrofluoric acid wouldn't work, are there any acids corrosive enough to achieve the stated effect from the show?
The real reason I brought up this episode of Mythbusters is that they have a storied tradition of reproducing the results at all costs. In this episode, at the end, they fill up a bathtub with 140 L of concentrated sulfuric acid, a "secret sauce", and a whole pig just to see what happens...
To borrow the words of the episode description from the link above,
After 5 minutes, Adam and Jamie found only black organic sludge where the pig used to be.
And, a word on the secret sauce. Intuition says that this is something which is going to be good at breaking down organic matter. I looked around and found some people speculating on this reddit post, and they come up with pretty convincing evidence that the "secret sauce" is just hydrogen peroxide.
Hydrogen peroxide is a good radical initiator, and thus should be quite effective at assisting in the decomposition of this pig/person. This mixture actually has a name: piranha solution.
So, to answer, yes, a mixture of $\ce{H2SO4}$ and $\ce{H2O2}$ should do the job.
I know Mythbusters and Reddit aren't exactly the standards of scientific authority, but in this case, I think they're doing pretty well.