I have used just about everything out there and the best sharpener is the Lansky. It's tedious to use the first few times because you basically hand-grind a new bevel on your knife but once you've got it sharpened it's scary-sharp. It may not be for you if you're the type that doesn't read and follow directions closely, or if you don't have the patience for it. I would say that it takes 30-45 minutes to sharpen your knife the first time with a Lansky, 5-10 minutes to touch it up once you've ground the bevels. If you like to show off by shaving the hair off your arm or ribboning paper, the Lansky is the best. Get an extra coarse stone, it will greatly speed up your first sharpening. I have found that the extra-fine stone (1000 grit) is not necessary--the fine grit (600) will give you all the edge you need, especially if you're hunting. The 600 grit leaves a very fine "tooth" to your edge that will "bite" into the material you're cutting whereas the 1000 grit leaves a highly polished edge that sometimes doesn't cut too well through coarser materials.
The Tri-Angle Sharpmaker by Spyderco is also very good, especially if you use serrated or half-serrated knives. I think Lansky has a stone for serrated edges but I haven't tried it because I use the Tri-Angle. If your knife gets really dull, to the point where the edge has rounded over, the Tri-Angle will not work very well.
The Gerber diamond sharpener is a good, field-expedient sharpener for touching up your knife in the middle of a job. It also does not require sharpening oil, so it will leave your blade relatively clean. The diamond sharpeners are usually a medium grit so your knife will not be razor sharp but if used properly it should give you a good, lasting edge. I use a fine grit diamond steel (12" long) in the kitchen and it's satisfactory.
When I use the diamond steel I try to maintain an even angle with the knife at all times. This necessitates a slower, more methodical stroke than what you see in the butcher shops, restaurants, etc (those guys are professionals with way more experience, obviously), so don't try to mimic their moves.
Old fashioned sharpening stones (even if they are made of space-age synthetics, diamonds, etc) work well if you have steady hands and patience. Again, just like with the steel, don't try to copy what you see on TV (99% of what I've seen is totally wrong). Read and follow the instructions.
Finally, don't waste your time with cheap China-made knives (Frost, Taylor, Chipaway, M-Tech, swap-meet specials, etc.) Buy a quality, name brand knife that suits your needs and it should last a lifetime. Some of the super-steels out there (154CM, S30V, etc.) are very difficult to sharpen. 440C (not just "440"), AUS-8 and ATS-34 make good blades that are relatively simple to sharpen. Puma and Boker from Germany are both good brands. The older Kershaws with Japan blades were very good, I haven't had much experience with the newer, China-made line of Kershaws.
I hope this info helps. What kind of knife are you using now?