I am having a hell of a time making this shape. It ether has tons of triangles that I don’t want or it has verts that are out of the circle causing strange shading failures.
Does anyone know a better way.
I did it with a cylinder and a second cylinder that was stretched in the middle to do a boolean cut out. Then cleaned it up for an hour. NOT the way it should be done for sure and it still has problems.
So what is your way?
Choose the appropriate amount of sides for both cylinders. Your cutout has way more vertices than the surrounding geometry, that’s why you’re having issues bringing it together without creating shading artifacts. For cleanup, symmetry is a great way of minimizing the work: after boolean, cut the model in half and use Mirror modifier, so you only have to clean one side. Knife tool, merge tool and vertex snapping are of great use here (maybe even to the point of using Automerge editing). Making supporting edge cuts can be sped up by using loop cut on both sides of the cutout, then knife tool to connect them, followed by Dissolve Edges to remove extraneous loops.
Attached .blend took about 5 minutes to make. The original geometry is on another layer. 48 vertices for the main shape, 16 for the cutout cylinder.
cylinder_cut.blend (116 KB)
Wow, beautiful. Could you spend another 5 minutes and do it as a video on youtube?
I used all the tools you talked about but still had problems.
Thanks.
Here you go: https://www.dropbox.com/s/4tng0y94wdewh18/cylinder.mp4?dl=0 
Tools used:
When doing multiple merges (like when I’m cleaning up the vertices around the cut), you can use Shift + R to repeat the last action, instead of calling up the Merge tool every time.
Very cool. It is amazing how much there is to learn in Blender. I have been using it for 15 years and still learn stuff.
Thanks!
You are welcome 
