This topic's been more beat up than Tina Turner dude.
You can go 195/50-15 with a wheel offset of 42-43 and not need spacers, that's what I got right now.
205/40-16, 205/45-16, 205/40-17 will most likely need spacers on the rear depending on wheel offset. 17s are overkill though and your car will ride like shit and feel very slow though. 16s are somewhat ok, more for show but still perform decent. 15s are really good for performance and look good on the car too. 14s are really more for performance than anything. Wheel offset 38-43 works best 45mm is possible.
I'm thinking of upgrading to 205/45-16s next summer, more show and less go.

you never know, I might sell my wheels