What are the "must see" in the Liguria region?

5 Terre Porto venere, Lerici, Montemarcello Golfo del tigullio (SMargherita, Portofino, Rapallo) Triora
Camogli And many more

Dolceacqua Castelvecchio di Rocca Barbena
Finalborgo

Well, the Cinque Terre (5 Terre) are certainly NOT off the beaten path and haven't been in many years. A "must see" and "off the beaten path" are mutually exclusive. If something is a "must see", you can bet a lot of other people are going to see it.

Some of the paths are less beaten than others....Hit the Sentiero Rosso to get away from the hoards, if you are avid hikers. We recently hiked form Monterosso to Levanto and found it quite peaceful: Hike to Levanto

I don't think the CT is a place to go for must-sees; it's more for must relax with maybe some light hikes between the towns as an activity. I've read some accounts of people who went inland from the coastal trail and found a much less beaten path. You might try that. Remember it's Italy - don't expect good signage.

The inland weave of CT trails doesn't take any longer than the coastal blue. It's maybe a couple more miles each way, and not quite as easy, but you're not distracted by the villages. You can still round-trip it six hours, seven easy even if you spur off to the coast for beer/lunch/coffee once. The hump isn't a gut-buster. I wouldn't make a detour to go back again.

We really enjoyed Camogli, Portovenere and Portofino (although they're not exactly "off the beaten path"). Camogli is probably the most "off the beaten path" but still very crowded in early September of this year when we visited. I enjoyed Portovenere more than I expected to and it's a very easy boat ride from the CT towns. Have a great trip!