The Enneagram Types (and the various names for them):
1. The Reformer / The Perfectionist
2. The Helper / The Giver
3. The Achiever / The Motivator / The Performer
4. The Individualist / The Romantic / The Artist
5. The Investigator / The Thinker / The Observer
6. The Loyalist / The Skeptic / The Loyal Skeptic
7. The Enthusiast / The Epicure
8. The Challenger / The Leader / The Protector
9. The Peacemaker / The Mediator

Type One - The Reformer / The Perfectionist: A one has strong principles and convictions, and an intense sense of right and wrong. Because of this they can be rigid and unforgiving. Their ideal is to always be rational, right, responsible, and to improve matters. Ones are the listmakers of the world. Ones can sometimes bite off more than they can chew, and feel that the burden of saving the world is on their shoulders. They can be tense and uptight, wary of making a mistake or disturbing their perception of how things can be. They expect excellence of themselves, and others, and can be critical.

Type Five - The Investigator: Type five is primarily an observer. They are very alert, intelligent, and perceptive. Their inner fear is that they aren't really strong enough to face the world and so they are prone to extreme detachment, and often live almost entirely within their minds. Fives strive to be self-sufficient. Being needed, or needing can seem like a trap to a five. Their mode of expression is restrained and they fiercely guard their privacy. Fives often have a lot more going on beneath the surface than others percieve. On the plus side, a five knows a lot, protects the secrets of others, and is very calm in a crisis.

Links: - Descriptions, tests (free) and links. Worth seeing.
Enneagram Central
The Enneagram Institute
The Authentic Enneagram