3x3 Clear Switch Tester Housing

For testing and comparing, personally I find this to be ideal.
The small size means you can compare a large enough selection with oneanother (namely using the same finger), and it's easier to keep track of what you have where.
Note that switches don't clip into the socket, so how well they grip depends on the housing - some, like Glorious Pandas, were a bit stiff to insert I'll admit.
But for purely testing purposes that's hardly an issue; and it makes it easier to swap and rearrange what you're testing.
(As an aside I've only used it for MX-style switches, so cannot comment if it works for others, e.g. choc)