Try searching for things like part numbers and datasheets for obscure electronic components, along with schematics and service manuals. That's one area where Google's search results used to be far better than now.

I've almost become accustomed to always putting my queries in quotes, just because it would otherwise mean completely useless results.

The other thing that's gotten worse results is... adult content, especially when searching for very specific terms; and even with "SafeSearch" off, which is supposed to mean no filtering.

To add insult to injury, repeating minor variations of a query, combing through "all" the results (or as many as Google is willing to show you), and in general trying to extract what you're actually looking for also tends to get you blocked with a CAPTCHA or just completely banned for a while.