It may surprise many on here to know that often Lufthansa can work out the same or even slightly cheaper than many budget carriers. For example I recently got a €99 return ticket from Frankfurt to Edinburgh, the only extra was a few €'s booking fee via Expedia. This often works out cheaper than their own Germanwings. You need to book well in advance (4-8 weeks) but the plus side is there are no nasty surprises like with some of the other budget airlines.