Costco gives you an extra 1 year beyond the Manufacturer's typical 1 Year warranty.
Many credit cards do as well, if you purchase with a credit card.
Square Trade is excellent.
Walmart offers Extended Warranties that have been solid as well, but Best Buy is probably a bit better as when they do trade ins, there is more selection.
Vizio VP322 Plasma / Vizio GV42LF LCD / Denon 2200 Silicon Image DVD / Panasonic S97 Faroudja Genesis DVD / Oppo 970HD Mediatek DVD / Oppo 983H Anchor Bay DVD / Panasonic LX-600 Laserdisc / Aiwa MX100 Multi-region VCR / JVC S7600 S-VHS / PS2 / Sega Genesis / Nintendo SNES / Roku 2 XS & HD-XR / Realistic STA-90 Reciever / Realistic Minimus 7 / Antennacraft G1483 Hoverman / Belden 7915A RG6 / Channel Master 7777 Titan 2 UHF/VHF / Panasonic AX-200u / Optoma Graywolf 92" / Draper Luma 92"