I have a Panasonic KX-TG6841 telephone. It will store 250 unwanted phone numbers. When they call a second time, the phone disconnects them automatically. I love it.
I have one also, love it.
Can block a range of numbers, entire area codes. When I start getting calls from area code 571 for instance, I program that area in the phone and POOF all calls from that area are blocked.