On http*://*google.*/search* I use four userscripts.
- Disable Google Search Result Redirect (#29812): disable tracking via google-redirects.
- Remove ads from google search (#176671): remove annoying ads above search list.
- Advanced Google Keys (#5711): navigate through google search with keys (arrows, p, n, t, numbers).
- SearchJump (#4233): try search also on other search-engines.
For most of them only google.com is treated by default, so you have to add the above filter.