Well no way you can do three it is really a 4 or 5 lens kit.
But if you must and I have had almost every lens at one point or another but it was mostly based around the 28 cron which was my lifeblood lens and the last lens sold too.
My favorite end of the day end of it's life for me was
Leica 21mm elmarit which has a nice look like the 28 cron . Kissing cousins
Leica 28 cron absolutely the best lens on the M8
Leica 50 prelux
If I had to buy a M8 again I would first get those lenses
4th lens after the fact
75 cron
5th lens
CV 12mm
Now if you like brittle sharpness than you could go for the Zeiss 18mm instead of the Leica 21mm. It's a different look
Just some lenses I had with the M8 Wate,Zeiss 18mm, Leica 24mm elmarit, Leica 28 cron, Leica 35 cron Version IV, Leica 35 lux, Leica 50 asph, Leica pre kux, 75mm Lux, 75 cron, 90 summarit, 90 elmarit, 90 cron, 135 elmarit and more than I can remember but at the end of it's life I had those 5 lenses mentioned earlier and those where my final choices.