Personally, my main thing is to spend a few days or weeks scouring the internet for good free drum machine samples sorted according to the drum machine model name. Most of the good ones aren't manufactured anymore, but their sounds are still around on the internet.
Then I mix and match several different drum machine samples and delete the crappy sounds. It's very labor intensive because usually most people include so many sounds, but after a while it pays off. Then I load up the good sounds, mix them together in ways that I like after tweaking the pitch and pan and render them to new samples and store them.
You can also sample from drum VSTi's and just keep the good ones from those too. A kick here, a snare there, a hat from somewhere else. It's all good once you pool them together. Sometimes I also use impulse responses as abstract snares too.
All the drum kits I ever bought were crap so I just don't buy them anymore.