Germany - Frankfurt Car Service Company

Hello - Does anyone have any recommendations for a reputable car service company in Frankfurt, one that provides excellent service? Looking to book a Mercedes S-Class for various transfers (airport, in-town, etc). I did find the following companies - if anyone has reviews or any other recommended companies, I would appreciate the help. Thanks

ETS
http://www.ets-frankfurt.de/

Gateway Limo
http://www.gateway-limo.com/

Move On
http://www.moveon-service.com/

Top Alliance
http://www.top-alliance.de/

United Limousines
http://www.united-limousines.com/

To answer my own post, we used Gateway Limousine in Frankfurt and they were great. Dimitrios the owner and driver is very professional and has a new Mercedes S class (black color, new shape , video monitors in the headrests, etc). He always arrives early and his prices are great as well. Much better service and response time versus some of the larger Frankfurt companies. Info below:

Gateway Chauffeur & Limousine Service
Tel.: +49 6102 206977
Mobile: +49 170 9604894
email: office@gateway-limo.com
www.gateway-limo.com