ivierre,
Ignore our fixed wing bretheren re engine failures, I'd rather be in a R22 looking for a small football pitch rather than trying to find a smooth, firm, long field. But more to the point, engines do not fail very often.
Your choice depends on two things: What you can afford and what you want out of your flying.
Someone more up to date than me will give you an accurate hire rate for an R22, but I think it is around £150+vat, instruction will cost another £50 -60 on top. Budget for at least 50 hours plus the cost of medical, books, exams etc. Once you have a ppl, try and fly at least an hour a month, although I would try for at least an hour a fortnight - it is just too much fun to do any less! Remeber this is just for an R22 (two seater). For greater flexibility a R44 (four seater) rating is well worth it. Helicopters open up a whole load of hotels, race courses, and back gardens (careful here, big back garden not surrounded by houses only) where as fixed wing are bound to airfields.
If you want to go touring long distance and be less affected by weather a fixed wing might be better. Instrument flying (flying in clouds) is relatively cheap in fixed wing, IF for helicopters is in the realms of double lotto winners (if you buy your own aircraft, hiring an IF helicopter is not cheap and availability will be an issue).
If you want a career out of flying, check out the rotorheads forum for a huge thread on becoming a professional helicopter pilot.
Don't forget to look at other options, eg gliding and microlights. Aviation is expensive and it is a shame to spend all your money on training and have none left for flying once you have your license.