GL 3.x is my current go to for the case of needing simple immediate mode 3D rendering. But it's still Bring Your Own Matrices/Texture Loading/Text Rendering/Model Loading, and D3D9 + D3DX had that all in a nice package. Like I said, stitching this stuff together isn't the hardest thing ever, but it's nice to have a basic set of boilerplate that's idiomatically consistent and works out of the box.
