stated as a question,"amiright" is a declaration of correctness even when wrong. Most often used when giving a socially accepted opinion. "amiright" is also used to humor those taking the statement too seriously.
Often followed by a 'high-five'... a "amiright" can be either be false of truth. OR a sarcastic dismissal.
"that bitch is cold. amiright!?" *high-fives ensue*
"I'm so drunk I could fuck a panda." *awkward looks* "amiright!?" *high-fives ensue*
"I worked so hard my dick fell off, amiright!?" *awkward looks* "AMIRIGHT!?"... *reaches for high-five*