I am not an attorney nor an accountant. This is not "professional advice".
An S-Corp is like a pipe you run water (revenue) through for tax benefits.
An LLC is a more rounded entity.
If you're planning to raise money, issue stock, or sell the firm, the LLC is the better choice.
My accountant recommended an S-Corp which has served me well for the past few years. But there will come a time when my revenue exceeds a certain level, and it will make sense to make the jump to an LLC.
These are two good articles on the topic:
(very good on exit strategy discussion)
(in-depth S-Corp discussion).
The S-Corp suits me well right now as a primarily service/consulting business where I usually work alone.
I'm neither a lawyer nor an accountant. You should definitely ask one. Check out www.TheVIPLawFirm.com which supports clients across the country relating to venture and business law.
The short answer to your question is likely "it depends." It depends on the goals, whether you already have a lot of assets or investors and how you plan to conduct business. In many instances an LLC with an S election may be simpler than an S Corp which has formalities like annual meetings and are likely more cumbersome to a solo entrepreneur or a small number of people operating a small business.
Laws on business entities also vary from state-to-state. Understanding the most favorable scenario for you will vary based on where you form your entity.