It wonders me that so many equals low cost carriers with being no frills carriers. Since Norwegian Air Shuttle has been mentioned here, it's definitely not a no frills carrier but they have low costs due to a slim administration, innovative use of information technology and intelligent revenue mangement. Use of new 186 seat B738w also contibute to lower costs although they have the same Recaro seats as many legacy carriers have and the leg room is equal or better than most legacy carriers due no extravagant gallies, closets and extra leg room up front. You have pay extra for checked in baggage and reservation of a seat, but then don't need to wait for this seat reservation until it's 22 hours before departure - you just reserve the seat when you pay for the ticket. As long as you use a debet card you don't need to pay for paying the ticket (no extra charge). If you want to bring with you your bike or your golf bag on a vacation, the extra charge for this is lower than most of the legacy carriers. When you are inside the cabin you aren't bombarded with a sticky yellow colour, or saturated red colour, or overhead bin doors plastered with ads or a large letter destination overview. The only colour splash in the cabin in addition to the dark blue leather seats is the small red headrest cloth with a Norwegian logo on it. As someone here mentioned on most flights (not flights flown with the few -300s left + a few leased older -800s) you get free Internet in stead of the free newspaper that some legacy carriers offer (again new tech vs. old tech). Through the same WiFi connection it will now be possible to rent videos or music for a small extra charge; you need only to log on to a server on board through the portal with your own device (BYOD technology). The crew on board can smile and they will help in any way they can, but they don't push BOB or lottery tickets - on the shortest domestic flights they don't even offer BOB. You will never be exposed for a cheap on time fanfare. If you want to travel from let's say Bodø (BOO) to Gatwick (LGW), Norwegian offers a through ticket (via OSL) and the next time you see the baggage you checked in at BOO is at LGW.
In other words Norwegian offer a strait forward honest service, and with a punctuality equal to the best of the legacy carriers and a regularity better than most of the same carriers. It is pretty certain that you arrive at your destination on time and that for a reasonable price. What more can you ask for?