Here's what it's like to fly with RyanAir, one of the world's most notorious airlines

RyanAir might be the "world's favorite airline" based on the number of passengers it carries per year, but it's still notorious for being unpleasant to fly on.

One index rated RyanAir the second-worst brand in the world for customer service last year. The Dublin-based airline has drawn so much ire from passengers that one set up a website with the URL "ihateryanair.co.uk" and was later forced to forfeit the web address to the company.

RyanAir's bad reputation isn't very surprising considering it once announced plans to charge passengers to use the bathroom (which the company later dropped).

Flying with RyanAir is predictably frustrating in many ways, but the service wasn't so bad that it deterred me from booking flights with the airline while I was living in Europe. The rock-bottom prices keep customers coming back, and I don't know of any airline in the US that lets you fly to another country (or another state) for $20.

I flew with RyanAir several times over the past year, and I did notice some differences from more traditional airlines.

Hands-down the most frustrating thing about flying with RyanAir as an American is having to go to bag drop to get your boarding pass stamped.

Even if you're not checking anything, non-EU citizens have to get a "visa check," which means waiting in the long line for bag drop to have an airline employee behind the desk check your passport.

You also can't get a mobile boarding pass if you're not an EU citizen, which means you have to remember to print out a paper boarding pass before you head to the airport.