The last paragraph should bring the cover letter to a polite conclusion. It should also STRESS ACTION. Finish strong and quickly. Remind the recruiter what you introduced in the 1st and 2nd paragraphs (how your experience or skills will help the company).
That's the point of a cover letter: a call to action. Inform the recruiter that you'd love to get interviewed too. But be careful – if the last paragraph goes longer than that, you're just rambling and weakening your call to action.
Example: "I hope to have an opportunity to meet with you in person to discuss how my skills could contribute to [Company Name]'s goals.