"Gateway to success."
Translation:Είσοδος στην επιτυχία.
Hm, I'm on the fence about this one. To me, it would be even better if part of this phrase was something like προς την επιτυχία (towards success), no? ^.^
"Προς την επιτυχία" is also a very good interpretation. In my limited experience, expressions using "Gateway to ..." are not often used in Greek conversation. More often I hear "μέσο ..." being used as an equivalent expression to the Anglo "gateway".
Sometimes πύλη is also used. Η πύλη για την ευτυχία=The gateway to happiness, and I think that is the most accurate translation, as gateway is πύλη.
"Πύλη" is another good option. There is something grandiose about that word. How about he word "θύρα" that is in common use for "gate" in airports.
Θύρα is not used with the meaning of "gateway" but it's used as you said in the airports, stadium gates and PC ports.