I have my Laptop plugged in my TV via HDMI (Vaio and Samsung) and it's crystal clear. As good if not better than any monitor I've ever seen or owned. I assume it is also still a much cheaper option, as last time I bought a very large widescreen monitor it cost the earth.

However I used to have an acer Laptop and that looked bloody awful on a TV. So I'd imagine reading up heavily on the graphics card beforehand will help.

Between myself and the rest of my family we own at least 5 different sizes and models of Samsung HDTVs and they are all great with whatever you plug into them, in my experience. iPhones/Digiboxes/DVD & BR players/HDMI PCs & Macs/old PCs/Hi-Fis etc