There are a huge number of different dumbbells on the market these days. Which ones you get will depend on what you want from your workouts. If you want to build muscle then you will need dumbbells that are 1) Heavy and 2) come with additional weights. You will need to have the additional weights because as you build the muscle you will continually need heavier weights in order to see any improvement!If you are looking for dumbbells in order to tone up your muscles then you could be best off just getting one set at the weight that is most suitable for you.Have a look at Review site by Daniel for more info on this.
There are also special types of dumbbell weights that you can use for different activities, you can take extremely light dumbbells with you when you jog to make it a bit more challenging.Or there is the incredibly innovative shaking dumbbells that are said to increase the muscle toning and definition 300% compared to normal weights There is also the price you must consider, some of the really good dumbbells can run you as much as $400 (but then again these are the very very best that money can buy!), so you need to think about how big of a role your dumbbells are going to play in your workouts to gauge whether or not it is worth spending so much on them.