If it’s a project I already have open in VS Code, I won’t use a separate tool.
If it’s a single file I want to check out, I have an alias for “nvim -R” which I use a lot. Vim’s syntax highlighting is very good, prevents me from making accidental changes, and is very convienent if I’m in the terminal already.
If I’m looking at code on GitHub then their code-search feature is very cool (cs.GitHub.com or by pressing cmd+shift+f on GitHub).