You have the various focal lengths pretty well covered. While there are better quality lenses, they aren't necessary in many circumstances. Some lenses are more expensive because they may have built-in silent auto focus motors. While nice, it doesn't affect image quality.
There certainly are lenses with better optics that will indeed give higher image quality -- But it's often a fine difference not necessarily noticed in a quick glance. If you're simply looking at Facebook pictures, or 4X6 prints, you may not even notice the difference between a $200 lens and a $2,000 lens. If you are blowing up huge prints, if you are pixel peeping, or if you are shooting in much more challenging light, that's when you really notice the differences.
My favorite lens for portraits and family shots, is actually a 25+ year old used lens that I bought off Ebay for $90. (I don't shoot Canon).
Don't get me wrong, I have a decent amount invested in lenses. But the key to great portraits isn't always a super expensive lens.