If my company has what is called a "cafeteria plan" and they failed to offer me insurance this year, what are my legal options against the company?

No options at this time. Many employers are adjusting their "cafeteria" options in anticipation of the change in obligations based on "Obama-care."

I do not know of any remedy, other than to go get your own insurance. Many companies are electing to do this, and requiring the employees to become part of "Obama Care" Nothing in the law requires them to do this, but many employers really want to get out of the insurance providing business. They may lawfully do this, at their election.

Did they offer insurance to anybody? If not, then I guess it is no longer part of the plan. If just you, there has been a mistake and you need to talk to HR.