First off you need to decide how much lift you need.
Are you just trying to "level" it or do you want a lift to accomodate bigger tires?
Is your vehicle a 4X4?
The most important question is: what is your budget?
Everyone is going to have an opinion on what works but it is best to start with a budget and find something that is in your price range.
Many spacer lifts require the use of a spring compressor (which is tricky).
Many people have also used spacers from
extremetrucktoys - Specializing in lift kits
Some really nice looking/inexpensive ones are located on eb@y (item#180173043264)