Get 17,500 bonus points when you sign up for the US Bank FlexPerks Travel Visa Card and spend $2,500 within the first 5 months. Plus, you'll earn a point per dollar on the $2,500 you spent, netting you a total of 20,000, enough for up to $400 towards airfare at over 300 airlines. Better yet, you'll earn double points on all your purchases on the category you spend the most on each month (choose from gas, groceries or airline tickets) plus most cell phone expenses, and triple points on charitable donations. Other perks include a $25 travel credit through their award ticket program, a free car rental, and more. There's no annual fee the first year (after that, it's $49).