Sinn was one of the best-kept secrets among watch fanatics for years until about 2002, when the brand caught fire on the Internet. Widely perceived to be a new brand, Sinn has been making watches for professional use in Germany for almost 20 years. Stories abound about people flying to the Sinn factory in Germany and buying 20 or more watches, and then selling them to their collector friends and/or on eBay. Now Sinn is more widely available, and to their credit, prices are still low compared to the high quality. Popular models include the Sinn 356 pilot's chronograph, Sinn 956 Rallye chronograph, Sinn EZM models, Sinn 103, Sinn 144, and the Sinn 903 which is inspired by the famous Breitling Navitimer.

Here is a fun website where you can vote for your favorite Sinn model

Hacmac's 142 review

Review of the Sinn 156

Great review of the Sinn 156

Review of the Sinn 157

Review of the Sinn 103

A truly great review of the legendary Sinn 356

Review of the Sinn EZM 4 Achilles firefighter's watch written by a firefighter