Both Dell and Lenovo offer on-site service where a tech comes to you. It's an upgrade from their "standard" warranty service, but totally worth the extra $, especially if you rely on your computer.
In addition, they both have "accidental damage" with some of the higher-end warranties, so they'll cover you e.g. if you spill soda in your laptop.
For what it's worth, Apple also offers on-site with AppleCare.
And then in the cases for certain quality programs, such as the iMac hard drive replacement [1], they will do on-site even if you don't have AppleCare and/or are out of your 1 year warranty.
And then in the cases for certain quality programs, such as the iMac hard drive replacement [1], they will do on-site even if you don't have AppleCare and/or are out of your 1 year warranty.
[1]: http://www.apple.com/au/support/imac-harddrive/