Don't watch it without knowing what you're getting into. That movie is a mess.
The original cut is lost, and there is pretty much no chance of it turning up in some seemingly random spot. It was almost certainly destroyed, and I wouldn't be surprised if it was deliberately set on fire. Unless I get my hands on a time machine it is gone forever.
A second director reshot the movie, and significant portions of this second cut are also lost. I do not know if any footage from the first cut was used in this version, or if they reshot the entire thing.
That second cut was eventually edited down by a third director, and that third cut actually still exists! Only 16mm prints survive though, so it's rare. Unfortunately most of the companies that release restored silent movies only work with 35mm prints. Normally that's good because it means better quality releases, but in Phantom's case it means they usually ignore the best surviving version of the film!
That third cut made great money, so when sound came around they got most of the actors back together and reshot a sound version so they could put it back in theaters and make more money. Aaand it's lost. Mostly. Some of the sound did survive and, uh, we're sorta not sad about this one being lost. Sound acting wasn't great yet.
Then... we
think they edited a silent version of the sound version so they could release it in theaters that didn't have sound equipment yet. It seems odd that they wouldn't just rerelease the silent version they already had, but the sound version is shorter. Maybe if a theater had some sound rooms and some silent rooms this allowed them to play two versions that were the same length and could have identical scheduling. I don't know. All we know is a 35mm print that we
think was used for this purpose was discovered in great condition, so that's what everyone uses. If you see a DVD or a Blu-ray, or see it on TV or even a special theater showing, it'll be this one. Just because of the picture quality.
So if I recommend that you see this movie, you're probably going to end up seeing a weird edit of a reshoot of an edit of a reshoot.
That said,
this is the one I recommend watching, if you watch it at all.
As for other silent movies, eh. You have probably already seen everything that is worth seeing of Nosferatu.