Everlong (acoustic version) - Foo fighters
The last couple of songs I’ve added to my Guy With Acoustic repertoire are “Hey Bulldog” by the Beatles (play around with it–you can make it work) and “New Amsterdam” by Elvis Costello (which requires some vocal range–I strain a bit at the top, and can’t do it sitting down).
Peaceful, Easy Feeling - Eagles. You can dink around with the guitar quite a lot when doing it as a solo piece.
Darcy Farrow - Tom Campbell and Steve Gillette. John Denver recorded this and his arrangements, I think, are really great for a solo guitar. Good fingerpicking here.
Time Passages, Song on the Radio, and End of the Day - Al Stewart. Lots of good picking here. Actually, old Al has a bunch of good stuff that can be arranged and played on solo guitar quite nicely.
Pretty much all of Gordon Lightfoot’s work.
And if you want to experiment with open tunings, look at Will Ackerman’s work.
4+20 - CSN (take an alternate tuning, like most CSN songs, but is a damn nice song)
Canon in D (it’s best to used a drop D tuning. This is my all time favorite song to play)
Sunshine (go away today) - Jonathan Edwards
Sunshine Superman - Donovan
Over the Hills and Far Away - Led Zeppelin
Gallows Pole - Led Zeppelin
Fire & Rain - James Taylor
Box #10 - Jim Croce
Gunga Din - Jim Croce (pretty rare. I’ve only heard one recording of it and it was really old. I think it was recorded when he was in college)
My Friends - RHCP
Life by the Drop - SRV
I’ll think of more, but those are some of my favorites to play.