Vienna Sightseeing has the most organized and extensive list of tours, including full-day excursions to Prague and Budapest and hop-on-hop-off daily service around the city. Most of the tours by this company are rather ordinary tourist fare you will find in any major city. They use good quality, clean full size buses and multi-lingual guides. The tours to Prague and Budapest are endurance tests at about 14 hours - 10 of which you will spend on the bus.

Royal Tours offers only full-day trips to Prague, Budapest and a couple of others. These tours are small - usually no more than 8 participants and one driver/guide. You won't have much room to spread out on the minivans so be prepared to really get to know your fellow travelers. The minivans are not as comfortable as a full-size bus and can often smell a bit smokey (cigarettes) depending on the habits of the driver and passengers.

ABC, offers minivan and private car tours (Mercedes E Class) for a slightly higher (minivan) or very expensive (private car) price. This company only works with Vienna's better hotels, for those who prefer a more upscale clientele and experience. Expect to pay between 40 and 110 euros depending on the length of your tour. For a private car, plan on about 75 euro/hr.

EXETER INTERNATIONAL is a leading tour operator specializing in deluxe travel throughout Central and Eastern Europe including Russia and Central Asia.  Recently featured in Condé Nast Traveler - 5 Perfect Days in Austria which you can read here  Exeter International's award winning team handles both individual and group travel offering the highest quality lodging, transportation, and unparrelled expertise and knowledge of the region.