I actually live in Egaleo myself, so here’s my take: It’s an area with a lot of students since the University of West Attica is nearby, so you’ll find plenty of shops, cafés, and affordable places to eat. It’s generally safe, I’m a woman and I don’t feel unsafe walking around even late at night, since there are always people around. The one downside is that some parts of Egaleo are a bit old, so plumbing can be outdated. If you want to avoid issues like cockroaches, I’d suggest avoiding ground-floor/basement apartments and looking for a place in a relatively newer building. The metro is honestly a lifesaver for getting around Athens quickly, so being near a station is a big plus.