I used to use a Leigh, but sold it eventually. It was an accurate and reliable jig, but I preferred to cut by hand rather than have that "machine cut" look.
I now use a Wood Rat, or for a quick, one-off job use handtools. The Woodrat delivers an authentic looking result, but it does need quite a lot of "fettling" and you shouldn't think of it as a tool that'll deliver great results straight from the box.
There is one other dovetail jig that I sometimes use for boxes and small stuff, the Gifkins dovetail jig. It's a fairly unique bit of kit as you use it with a router bench, but if you have a router bench permanently set up in your workshop it's probably the quickest and most convenient solution. The results are great, for wood up to 10mm thick you can use very pretty dovetail cutters with a 6.5 degree angle and you can introduce some spacing variability to the layout.
There are however some notable restrictions with the Gifkins jig, the pretty 6.5 degree dovetail cutters will only cut up to 10mm thick material, thicker than that and your back to 8.0 degrees and a more "machine cut" look. The widest board it'll take is about 300mm. And it'll only produce through dovetails, so unless you want to attach a false front it's not much use for drawers and is more of specialist box-making jig for producing dovetails and comb joints.
