Depends what I'm doing. Sometimes I need to edit as well as just view them. I have seen the Atom text-tail plugin that keeps getting mentioned but when I went to install it the homepage says Atom now copes with large files so it's been depreciated... I have to be honest, at this point I lost interest and went back to sublime.

Call me old fashioned, but the #1 feature I want from my text editor is the ability to edit plain text files... everything else is gravy (though syntax highlighting and regex's are two "features" I really like).

Amusingly (and only tangentially related), I just realised that notepad.exe on windows 7, which I always remember balking at files in the single MB range copes with my 100mb test file amicably and only chews 225mb of ram (21mb for my 10mb test file).