Business credit card rewards, best card ?

Chase Ink cards as mentioned are great for sign up bonuses. You can do them multiple time a year if you want. Ink Cash has 5% on internet, cable, and phone services. Also 5% at office supply stores up to $25k spend. The Ink Unlimited has 1.5% everywhere. The Cash and Unlimited are at 90k points for $6k spend. I wouldn't get the Ink Premier. It is only cash back and the points can't be moved to other Chase cards to send to travel partners. The Ink Preferred is 100k points for $8k spend and it gives you the ability to transfer points to travel partners.

It really depends on what you want out of the card. Will you keep it long term? Will you travel a lot? Do you have high spend?

I used to have an Amex Business Platinum. I guess I still do, but I don't use it as much. I switched over to a Cap One Spark for 2% cash back. I come out way ahead on that compared to the Amex.

Capital One Venture X Business card Is offering 300k if you spend $100k in the first six months.