You'll probably get a lot of differing opinions.

While I prefer plain black sights, I have used night sights before. If I were going to go with night sights again, I'd get something with a tritium dot in the front sight and plain black rear sights.

Ameriglo has some good options and consistently get good reviews from what I've seen. For tritium front/black rear combos, I like their Hackathorn model, which is available for the Shield.

Just my opinion, for whatever it's worth.