I cycled my cable modem several times a month to get my connection back, til it crapped out completely and I got one of these. http://www.newegg.com/Product/Product.aspx?Item=N82E16825122003 (Except it wasn't down to $40 at the time.) And its been solid now for several months.

Also, some troubleshooting that helped one day that was so obvious I didn't even think it was worth trying... if you have a cable that screws into a faceplate on the wall, make sure it's screwed tight.