The 75% Lens
This is by far my most useful lens outside. The focal range covers small landscapes, street shots, group shots, body shots, head shots, and really flattened out head shots. Will you get amazing soft backgrounds? No, but neither does it cost $4k.
IMO, once you have a reason to buy your first lens after the 50mm, get this. Easily the most affordable for the range and quality. You can absolutely own just this lens and impress 99% of people. With the exception of ultra wide-angle, macro, and super far distance objects, most everything else is just style.
If you’re traveling on vacation, for most people, this is the only lens you need. If you can’t articulate why you need something else, and why it’s compelling, this will do the job.