In the speech class I took last year there were a few that were especially memorable to me.

They were speeches that either could be seen from two different angles or were about unusual things.

The different types of speeches we gave were informative, persuasive, and business. I found the persuasive ones to be most interesting because, of course, they employed a lot of emotion and intriguing facts to hook the audience. Plus it involved more brainpower; you had to engage yourself as a listener.

* Speeches I've seen before and were great

Informative (something of interest to your audience specifically):

How to build a pond*

How to cook Thanksgiving dinner

Anorexia

How anthrax works

Dreams

Tattoos

The best roller coasters

Donating blood

Obscure diseases*

Adoption or foster care*

Persuasive (compelling and capable of being seen from both sides):

Immigration

TV and other media ratings

Internet

Vegetarian lifestyles

Salaries for certain occupations

Pitbulls*

Sex education

SUVs*

Drug legalization*

Women in combat

Mandatory immunization*

Personal ads/classified ads in papers/online

Overpopulation