We know, we know, grooms don’t have the endless options of a bride when it comes to a wedding suit (which is probably why 'groomzillas' aren't so much a thing), but you can play around with colour, prints and accessories to throw some personality in there. The crucial part is really to ensure a good fit - get that right and whatever your choice of suiting, you’ll look great. Also, go for a matte fabric, not a shiny one. Matte cloth absorbs light rather than reflecting it, which looks way better on the day and photographs well too.
Consider both your bride’s dress and her wishes. Of course, it's bad luck etc so most grooms don't actually see the bride’s gown before the actual ceremony, but you should check with her for a vague idea of the tone of her wedding dress, and if you should stick to the classics, or have freedom to veer from strict tradition.