Depends on two main things.
What do you call "not heavy"? Most good ISPs have different prices for different monthly download/upload amounts.
Second, what exchange are you on? Best to post a link to the results page of asking
samknows.
Third question is how much are you willing to pay.
(Isn't this a funny place to be asking this question? Surely
Which ISP would have been better. I suggest you actually delete the opening post and re-post there, with the replies to my questions included. Then I'll delete this).