If need to choose 1, I'd say the Sony 35/1.8, assuming you still have the kit lens for wide shots.

The Sigma is great (just bought one myself) but I tend to prefer a gallery where most photos are taken with 35mm with a few wide angles here and there. If there are too much wide angle shots it kinda seems a bit boring. Again, just my opinion.

35/1.8 looks like a big difference over what the kit lens can do. At 16mm the kit lens is quite decent in good light, so the improvements of using the Sigma 16/1.4 is not as big.

This post has been edited by dvlzplayground: Mar 18 2018, 11:25 PM