(Sorry if someone already made a thread for this or the information is already on and I just didn't see it).
I noticed that the Charisma section is missing information on what interactions that Sims gain as they increase their Charisma level. So I found this handy chart at The Sims Wiki:
Level Ability Type Notes Requirements
Friends Relationships
1 Friendly Greet Greeting Friendly greeting 0 0
Charming Introduction Special Boosted starting relationship. Level 10+ gives instant friendship
2 Amusing Greet Greeting Funny greeting 0 2
3 Interesting Greet Greeting Impressive greeting 1 3
Get To Know Special Gives increased ability to find out traits and interests (with the Friendly Trait, there is no level req.)
4 Flirty Greet Greeting Romantic greeting 2 4
5 Affectionate Greet Greeting Romantic greeting 3 6
Smooth Recovery Special Save conversation after awkward turn
6 Funny Greet Greeting Funny greeting 4 8
7 Impressive Greet Greeting Impressive greeting 5 10
8 Hilarious Greet Greeting Funny greeting 6 15
9 Loving Greet Greeting Romantic greeting 8 20
10 Irresistible Greet Greeting Romantic greeting 10 25
(Sorry, I don't know how to create a chart and the post page is bugging up).
(EDIT: Ohr, you can take this link:
http://sims.wikia.com/wiki/Charisma)