This one is clear 5 star winner. Its very often listed between the best free compressors and really deserve this position. From technical audio measurement it is better then very good AO compressors and comparable to best paid ones in the industry.
There is more advanced paid version of this plugin - Its worth every penny.
Nice-looking interface and easy to use, but I prefer their DC1A compressor. Similar idea (two knobs, a couple of modes), but feels more intuitive to me. I'd say stick with the one you prefer - you don't need both.
Super intuitive and simple to use the MJUC jr is a Vari-Mu compressor that everyone should have in their arsenal. Even if it's limited in his functions this compressor is useful in several situations. I love it with the fast setting on snares, it's also gentle and precise on vocals and acoustic instruments. I also use it when I want to add a little bit of compression to a channel strip, an amp or to another compressor, in fact, it's one of my two compressors in my "sandwich" technique (comp-eq-comp). The only way I don't use this compressor is on overheads, group of instruments, reverbs, mix bus, sub-mixes, parallel compression. I feel that with multiple sounds it starts to sound unpleasant to me and shows the limitations of the free version. That's why I'm going to buy the full version, that, by the way, has a ridiculously low price for what it does. This is a MUST HAVE. No doubt, click download and you won't regret it.