Depends.

Are you looking for the best sign up bonus? The most valuable points?

What kind of hotels do you like staying at? Biz or pleasure?

I have both the IHG and the Hyatt. I haven't used either since getting and using the bonus. I keep in the sock drawer for the free annuals.

Used both to patch together a nice week long trip to AMS and CDG. (80k points x 2--wife and myself--was four nights at the Intercontinental Amsterdam. Chase Hyatt gave me 2 nights at the end of the trip at the Park Hyatt Vendome. Almost $4k in hotels...)

So, for a sign up bonus, I like them both equally.

For long term strategy, I like the IHG because of the 2x gas, groceries, restaurant categories. Hyatt card is hard to earn points (unless you stay at Hyatts a lot--but, again, they don't have a big footprint).

Not a fan of Marriott...