My personal favorite is WindowGrid.
I too used the original sizer, and a few years ago I found it's updated sibling Sizer4, and the search eventually landed me with WindowGrid.
It splits the screen to a predefined grid, and then with a simple mouse gesture (while dragging the title bar, right-click the mouse, drag, then release) you can place the window very quickly and very easily.

If that doesn't suite your fancy, there are a few other solutions out there that might be of interest:
- As mentioned by modlin -
Microsoft PowerToys
has FancyZones
which is pretty awesome.
- If you want cutting-edge, check out the Windows 11 preview, it has a new feature the call Snap, which will make the maximize button do some screen positioning magic - this one feels closely tied to above mentioned
FancyZones
.
- AltDrag
- Preme for Windows - I actually use this alongside WindowGrid, for it's other features.
** While WindowGrid and Preme havn't been updated in years, I've been using these for a long time on Windows 10 and Windows Server environments, and had no issues with them. Hope they are still useful when you (and any other reader) reads this.