I did not realize how, outside of Iraq and Iran, how many more Sunnis there are than Shias. I kindof feel I should have known that, but there you have it. Click on the map for a larger image.
The map is a scan of a CIA-created, public domain map downloaded from the Perry-CastaÃ±eda Library Map Collection's World Maps series found via Wikipedia.
By some estimates, approximately 15% of the world's Muslims are Shia. There are an estimated 130 to 190 million Shia Muslims (including Twelvers, Ismailis, Zaidis) throughout the world, about three quarters of whom reside in Iran, Pakistan, India, Iraq, Azerbaijan, and Afghanistan. 
A large portion of the world's Shia live in the Middle East. They constitute a majority in Azerbaijan, Iraq, Bahrain and especially Iran, where 90% of the population is Shia, giving it the highest percentage of Shia Muslims of any country in the world. In Lebanon Shia form a plurality, and they remain as significant minorities in Afghanistan, Syria, India, Pakistan, Turkey and Yemen. Among the smaller Persian Gulf states, Qatar, Kuwait and the United Arab Emirates also have significant Shia minorities, as does the Eastern Province of Saudi Arabia.
About 20% of India's Muslim population is Shia, and significant Shia communities exist on the coastal regions of West Sumatra and Aceh in Indonesia (see Tabuik). Shia presence is negligible elsewhere in Southeast Asia, where Muslims are predominantly Shafi'i Sunnis.
According to the Shia, one of the lingering problems in estimating the Shia population is that unless the Shia form a significant minority in a Muslim country, the entire population is often listed as Sunni. The reverse, however, has not held true, which may contribute to imprecise estimates of the size of each sect. For example, the 1926 rise of the House of Saud in Arabia brought official discrimination against Shia . The Shia-majority areas of Al-Ahsa, Qatif and Hofuf on the Persian Gulf, and western Arabia provinces of Jazan, Asir and Hijaz, that had large Shia minorities, have officially been completely stripped of their religious identities. Some Shia claim that they endure much bigotry and other indignities from Walmen authorities daily and that Shia pilgrims from other countries are often singled out for harassment (see Status of religious freedom in Saudi Arabia); in Saudi Arabia they are called accaf (Ø¹ÙƒÙ) which means rejecters (Ø±Ø§ÙØ¶Ù‡).