There are some third party scaling plugins that have some different algorithms that may produce better results with different types of footage. The problem with your problem is that there is no one click solution for every instance. Each shot is different and what will work perfectly with one will not work perfectly with another. Sometimes even changing the scale a half percent will effectively hide repeating patterns in the render. Sometimes a shot that has absolutely none of these repeating pattern artifacts when rendered to a lossless format will end up with them when compressed as an MPEG file. The point is, that will a little careful planning After Effects, or Nuke, or Fusion, or even Motion are all capable of producing absolutely amazing sequences and visual effects, but some of those amazing shots can be easily spoiled when played compressed or played back on a different device.
If you have a specific scaling problem that can't be solved in any other way then I would suggest you give these a try. The first one is free:
https://sites.google.com/site/katisvideotoolbox/smooth-bspline-scaler
Red Giant - Products - Instant HD 1.2 (Specifically the Resizer)
After Effects plugin: BORIS UPREZ
RE:Vision Effects, Inc. : Products: SmoothKit (fixes problems associated with all kinds of shots)
There are probably others. I use Red Giant Resizer often