7. Bridge Constructor Portal
Bridge Constructor is a game about, who would have guessed, making bridges. Adding Portal mechanics to that works surprisingly well. Building bridges that allow people to get through test chambers is a lot of fun.
So why is it so low on the list? It doesn't feel like Portal, something that every game after this manages to at least somewhat succeed at doing.
It has the same problem as Pinball FX2: Portal Pinball, Bridge Constructor Portal's idea of a joke is to just repeat something from the other two games. Luckily it isn't as blatant as in Pinball FX2: Portal Pinball. In that game old voice lines would just be repeated, here they got Ellen McLain back to voice GLaDOS, mostly to repeat the same jokes but there are some new jokes, they're not funny, but the effort is at least appreciated.
This game is only worth playing for the most hardcore Portal fans who are happy to just have an excuse to see GLaDOS again. Or you know, people who just love building bridges.