Which languages have only 2 vowels?

The fewest amount of universally agreed-upon vowels used within a spoken language (because writing often does not reflect pronunciation, so the number of vowels used within a writing system cannot be trusted) is three, but none of these languages are very common. Clical Arabic and some Inuit languages, for example. There are a few languages where some linguists argue they only have two main vowels, but it's not something everyone agrees.