ML is driven by case studies and datasets. An overview:

Time-series:

1. • Economic:      http://www.economicswebinstitute.org/ecdata.htm
   

2. • Industrial:       http://homes.esat.kuleuven.be/~smc/daisy/daisydata.html
   

3. • TSDL:            http://robjhyndman.com/TSDL/    
   

4. • UK data:        http://data.gov.uk/about 
   

5. • EEG:             http://sccn.ucsd.edu/~arno/fam2data/publicly_available_EEG_data.html
   

6. • Mike West:    http://www.stat.duke.edu/~mw/ts_data_sets.html
   

7. • UWO:            http://www.stats.uwo.ca/faculty/aim/epubs/datasets/default.htm
   

Data mining:

1. • MLdata:          http://mldata.org/
   

2. • Duke:              http://www.stat.duke.edu/~mw/ts_data_sets.html
   

3. • UCI data:        http://archive.ics.uci.edu/ml/index.html
   

4. • MLDATA:        http://mldata.org/
   

5. • INEX:              http://inex.otago.ac.nz/, http://webspam.lip6.fr/
   

6. • PASCAL:        http://pascallin2.ecs.soton.ac.uk/Challenges/
   

7. • Clopinet:         http://clopinet.com/challenges/
   

8. • KD nuggets:    http://www.kdnuggets.com/datasets/competitions.html
   

9. • Delicious:        http://www.delicious.com/pskomoroch/dataset,
   

                          http://www.datawrangling.com/some-datasets-available-on-the-web

1. • Datamob:        http://datamob.org
   

2. • Ranking:         http://learningtorankchallenge.yahoo.com/, http://research.microsoft.com/en-us/projects/mslr/ 
   

3. • ed.ac.uk:         http://www.inf.ed.ac.uk/teaching/courses/dme/html/datasets0405.html
   

4. • Million Song:   http://labrosa.ee.columbia.edu/millionsong/            
   

5. • Nokia:             http://research.nokia.com/mdc
   

6. • Yandex:          http://imat-relpred.yandex.ru/en
   

7. • biomed:           http://datam.i2r.a-star.edu.sg/datasets/krbd/
   

8. • kaggle:            http://www.kaggle.com/
   

9. • Mindboggle:    http://mindboggle.info/index.html
   

10. • CAMrA:           http://2011.camrachallenge.com/
    

11. • Statistical Machine Translation:     http://www.statmt.org/
    

BioMed:   

1. • Statlib:            http://lib.stat.cmu.edu/datasets/
   

2. • StatSci:           http://www.statsci.org/datasets.html
   

3. • Klein book:     http://www.mcw.edu/biostatistics/Faculty/Faculty/JohnPKleinPhD/SurvivalAnalysisBook/DataSetsBothEditions.htm
   

4. • PhysioMed:     http://physionet.caregroup.harvard.edu/physiobank/database/         
   

5. • PhysioNet:      http://www.physionet.org/challenge/
   

6. • GLIMs:            http://www.sci.usq.edu.au/staff/dunn/Datasets/tech-glms.html