Is it worth buying LED, CFL or standard GU10 spotlights?

With the choice of LED, CFL, halogen energy saver and normal halogen spotlights, and so many different LED and CFL ones, what's the best? Is it worth spending over �5 on LEDs that may not be as bright as expected, �3 on the ageing but working CFL spotlights or just stick to the traditional ones? These are for my shop so I'm weary of spending so much on lightbulbs that might last longer than I'd need, which would be a complete waste and does the cost of the bulb really make up for the savings in electricity? Suggestions appreciated! I'd prefer a brightness that give an equivalent of about 35w (standard halogen).