The best juicer is the one that you enjoy using everyday. There is no one juicer that suits everyone so you need to decide how much you want to spend, and if your willing to put up with a bit of noise or would rather have a quiet machine that takes a bit longer to make top quality juice.
Wide Mouth Slow Juicer
It takes me under 10 minutes to make 4 cups (1 litre) of juice using a wide mouth centrifugal juicer including vegetable prep and washing up time.
Treat yourself to a quality wide mouth centrifugal juicer if you:
A masticating juicer uses a gentle crushing action, like our teeth chewing (hence the name) and is said to preserve enzymes and nutrients, creating extra healthy juice that keeps for 2-3 days in the fridge. While a masticating juicer often costs more than a centrifugal one, it will squeeze more juice out of your fruit and vegetables so you'll save money on your weekly grocery bill.
If you hate the noise of a centrifugal juicer then I heartily recommend a masticating juicer, which will gently crush the juice out of fruit, vegetables, and wheatgrass, rather than shredding and spinning them at high speed as centrifugal juicers do. A good masticulating juicer is really quiet. It purrs like a cat, rather than screaming at you like a banshee.
The juice produced by masticating juicers is more nutritious and if stored carefully will keep for 3 days in the fridge.
The downside with masticating juicers is that, with the exception of the new wide mouth models you do need to chop up your fruit and vegetables, plus they're slower at juicing so it does take longer to make your juice. They are built to last and usually come with at least a 5 year guarantee.
If you live in the U.S.A. then I recommend the Omega J8006 Juicer (See reviews on Amazon.com). It is much loved and gets excellent reviews. With a top qualify design the Omega J8006 makes highly nutritious juice that can be stored for up to 3 days in the fridge. This juice machine is built to last and comes with a 15-year warranty.