Budget?
I like the 19. Don't care that much for the 17, personally.
For plastic guns, the Walther P 99 AS is not a lot more money, and quite a bit better gun, imo, than the Glocks.
If you want metal, CZ 75 is a lot of gun for the money. The Hi Power is nice also, but more money, and might not be the best starter semi auto.