[to3m]

I've been happy with Everything, too. Everything is good because it searches by multiple substrings, so you can be precise about what you're looking for. (The much-loved fuzzy search, on the other hand, in my experience returns results that might as well be random, until you type so much of what you're looking for that you might as well have typed the whole thing.)

For searching file content I quite like Agent Ransack aka File Locator: https://www.mythicsoft.com/agentransack - main thing I like about it is that it's very quick and easy to see the content results from a subset of the file search results.