The full list of all Gaia Science Photometric Alerts can be found at http://gsaweb.ast.cam.ac.uk/alerts/alertsindex. The full list is also avaialble for download in CSV format from http://gsaweb.ast.cam.ac.uk/alerts/alerts.csv or you can download a copy from Alerts CSV page on this website. The alerts published during the validation phase (before July 2015) are also listed on the Gaia Photometric Science Alerts: Validation Phase page.
Gaia Alerts detections video
This is a movie showing Gaia Alerts detections over time (published before 14 November 2018) on the Gaia Data Release 2 sky map. (Credits: Sergey Koposov (video), ESA/Gaia/DPAC and the Photometric Science Alerts Team.)