I've got 3 chargers:
- DeWalt 20v 4-port rapid charger
- Ryobi 18v 6-port supercharger
- Milwaukee M12 4-port sequential charger
So much nicer than having 4+ individual chargers for each platform, or having to continually swap batteries. They all wall mount so I have them stacked on top of each other on a wall.
I started out thinking I was only going to use the DeWalt platform, but there are just too many advantages to using the best from multiple platforms.
DeWalt I see as top quality and buy most of my tools in this line that require either high end power or accuracy.
Ryobi I got into because of the value for tools you don't need great accuracy necessarily. Their OPE is top notch. Various styles of sanders are a great deal with green too. Plus they have some unique / uncommon tools like their inflator that blows up everything from tires to mattresses.
M12 because they have some great unique tools, and for other tools I want light weight instead of max power. DeWalt's 12v line has been lacking for years. The M12 ratchets and stubby impacts are awesome. And the M12 screwdriver is probably my most used power tool.
They all have periodic deals where they basically give away free batteries and chargers in packages with tools, so it's very easy to get into new lines and open yourself up to getting the best of all worlds.