I have tried many, but none have stuck with me as long as Divvy. Lot's of customization options, including one-off drag-to-size support, as well as user-defined keyboard shortcut support.

https://mizage.com/divvy/

https://manytricks.com/moom/

I use BetterTouchTool for both window management and some automation stuff. BTT is designed to add extra gestures and hot corners to your touchpad or mouse, which I have set to, among other things, take a screenshot if I press the top left corner of my trackpad and open Inspect Element if I press the top right side.

But BTT also has window management tools built in too. Drag a window to the right to snap it to the right half of the screen, left to snap to the left half, or drag to the top of the screen to go full-screen (without hiding the menubar). It's similar to the window snap features included with Windows 7 and newer, and works well. If you want only those features without the other BTT tools, the same dev offers the window management tools as a $3 app BetterSnapTool.

Then, there were also a couple other window management apps mentioned in another recent discussion about window management apps on Capiche:

• Rectangle which @jenlwei recommended as "one of [Spectacle's] newer alternatives
• Magnet which @alexjvale said is "something similar that's kept up to date.