You can't just say: "LEDs are better than fluorescent" or vice versa, in a generic sense. Modern power LEDs can do >100 lumens/Watt these days, and there's crap in either category. Most LED lamps on the market aren't just LEDs, but LEDs + power conversion circuit. Also it depends a lot on what you're using the lamp for, and what you consider most important. Tool shed / toilet / living room / street lighting / photography all have different requirements deciding what lamp is optimal.
So when comparing lamp types, it's more useful to say which exact type LED lamp you're comparing to which exact type fluorescent lamp. And with what application in mind.
Personally I think good LED lamps are about on par with good fluorescent lamps, but LED technology has more room for future improvement than already mature fluorescent lighting. And LEDs do away with some of the drawbacks of fluorescent lamps. But the long life of LEDs really begs for a separate driver circuit, so you don't need to throw away an expensive / long-lasting power LED when a cheap capacitor fails. :evil:
Environmentally, either LED or CFL is almost always better than incandescent (and probably halogen too). For example, just consider the amount of heavy metals that a coal power plant will put in the atmosphere (even if exhaust gasses are processed / filtered) to power an incandescent bulb over its life. The few milligrams of mercury in a CFL don't come anywhere near that. And that mercury is only a problem if the lamp's materials aren't recycled - which unfortunately is often the case. But that's not a fundamental problem with the technology. For example where I live CFL lamps are recycled, and personally I deliver worn out ones to a designated collection point.