This is perhaps the best known database to be found in the pattern recognition literature. Fisher's paper is a classic in the field and is referenced frequently to this day. (See Duda & Hart, for example.) The data set contains 3 classes of 50 instances each, where each class refers to a type of iris plant.

Source

Originally from the UCI repository

Medical charges in the USA. Average total payment based on state demographic data and 2012 elections winner in the state.

Source

• Demographics from Esri at Azure Datamarket

• Medical data from cms.gov

Dataset created from a study of diabetes in females 21 years or older and of Pima Indian heritage.

Pima Indians are an interesting population to study for diabetes because they have a higher incidence of diabetes than the general U.S. population.

Source

Pima Indians Diabetes Data Set at UCI Machine Learning Repository

Bitcoin is an experimental new digital currency that enables instant payments to anyone, anywhere in the world. Bitcoin uses peer-to-peer technology to operate with no central authority: managing transactions and issuing money are carried out collectively by the network. Bitcoin is also the name of the open source software which enables the use of this currency.

Source

Bitcoin Market dataset at Quandl

Appliance energy decision tree model

Medical charges in the USA. Average total payment based on state demographic data and 2012 elections winner in the state.

Source

• Demographics from Esri at Azure Datamarket

• Medical data from cms.gov