There are a lot of relatively inexpensive Specialty Grade "crowd pleasers" out there. Brazilian Cerrado coffees with there chocolate and notes of marzipan always go over well. Personally I would focus on seasonality and you will always find approachable coffees from nearly every coffee growing region and most every coffee growing country.
Studies using blind taste tests have always shown that a medium roast profile is the most preferred.
I'm guessing that you don't know what any of the 10 different people prefer. Will this coffee be a gift?
Your best bet would be to stay with a medium roast. People who prefer dark roasted coffee can adjust to medium roast, but people who prefer medium roast have a very hard time drinking dark roasted coffee, because it tastes totally burnt to them.
Besides trying Colombian coffee, Ethiopian Yirgacheffe may be something that more than half of the 10 people should enjoy.
And don't get locked into the idea that what they've been used to will be what you should roast. You may do better giving them something unexpectedly different/better.
Colombian Sup., Brazil Cerrado, or a Daterra., Even a good Guat. HueHuetenango or an Antigua.
I would roast full city or full city +.(medium to plus). They will all enjoy and appreciate some fresh roasted java.
I am sure they will ask for more!
Medium Brazilian Roast. I call this out gateway coffee. It's what we use to transition people from Folgers to good coffee. Once they are hooked they will naturally start experimenting with the harder stuff (African/Indonesia).
Also if you do find a roast/blend that is your "Crowd-Pleaser" try calling it your House Blend or Breakfast Blend. This will give you the freedom to interchange beans if there is a crisis (Colombian Truck Driver Strike) and will signal to most customers that it is a medium roast.