This will fit a Nalgene, most coffee cups, pint-size mason jars and also most phones and tablets. I've tried it in a few vehicles and it fits most of the car cupholders but is too fat for in-door cupholders.

My favorite so far is the solid one. It is a little pointy though, so a little edge sanding is a good idea. The solid one uses the most material but prints the fastest. The thin voronoi uses the least material but takes ~12 hours on my prusa.

No supports needed for any of these if you print with the skinny side down (as oriented in the stl).

update 4/22/22: V4 is a little larger to so it can hold even bigger Takeya and maybe Hydro Flask thermos.

V3 internal diameter is ~93 mm
V4 internal diameter is ~102 mm
V5 same dimensions as v4, tweaked the coffee cup handle accommodation and the phone holder