GCC Citizens - citizens of Arab Gulf Co-operation Council member states do not need a visa.
GCC Residents - AGCC expatriate residents who meet certain conditions may obtain a non-renewable 30-day visa upon arrival at the approved ports of entry.
Passport holders from all EU countries, Australia, Brunei, Canada, Hong Kong, Japan, Malaysia, New Zealand, Singapore, South Korea and United States will be granted a free of charge visit visa on arrival in the UAE.
The visa enables them to stay for 60 days. The visa may be renewed once for a period of 30 days for a fee of Dhs 500 (about US$140).
German Citizens (tourists and business people) may apply to the UAE embassy in Germany for a multiple-entry visa. No sponsor is required. The maximum duration of stay of visa holders should not exceed three months a year. The visa fee is Dhs 1,500.
US Citizens (tourists and business people) may apply to the UAE embassies for one to ten year multiple-entry visa. A sponsor is required and the visa will be granted free of charge. The maximum duration of stay should not exceed six months a visit.
Israeli passport holders are banned from entry and transit. Evidence of entry to Israel is generally ignored and not usually a problem.
The full story on visas for UAE
Some relevant visa information