For one non-time critical flight, easyJet will be fine. Like all the low fare airlines, when they're good they're really good value for money. When something goes wrong, well you just don't have quite the same service and backup level as with a full service airline.

Where are you flying from and to? Also look at Ryanair. bmi British Midland prices one-ways in the same way as low fare airlines. Or you might find it easiest to pick up a cheapie return from BA or someone else and throw one half away. Changing between any London airports, if that's what you'd be doing if you flew easyJet, can be pretty horrendous. The least bad is probably LHR/LGW.