American Express Platinum Card needs no introduction. It is the premier card in the AMEX line up that is available to everybody (with excellent credit that is). Elite status in Hotels, Car rentals, airline lounges… the benefit list is pretty huge. The Points Guy covers it in good depth.
The standard offer for Platinum card right now is 25K Membership Rewards (MR) points. However if you follow this LINK and apply, you can get 50K MR bonus points (Bonus ID 6751). Note that there is a 100K MR points targeted bonus out there and you may be bumped if you ask about it nicely (bonus ID 3882 or 5748). Read this Flyertalk thread for more info.