...the highest IQ and the smartest? I'll go for Dolphins.
Three weeks after captivity, they can teach people to line up on the very edge of the pool and throw them fish.
I think the dogs comes next. Much has been said of dogs that have saved lives, did it on their own without prodding from anyone. Just pure animal instinct and being smart.
I'll go with mice (bubuwit).
They can enter any office and when they go out they had lots of news and gossips. That's why media personnel/investigators always have one.
Chimpanzees, followed by dolphins. I recall watching a countdown of the top 10 smartest. Here's that list.
http://animal.discovery.com/tv/a-list/creature-countdowns/smartest/smartest.html