I'm having a little difficulty getting the exact RGB or html colour code from a pantone colour. Different methods give out different results. Is there a tool or chart out there that has this mastered?
Why do you need the RGB/HTML value? Personally, I wouldn't worry too much about it. Even if you do match a Pantone colour on YOUR monitor, it won't be the same on anyone else's. Just use Photoshop (Colour Picker > Colour Libraries) to get close, and write the Pantone name next to the swatch with a "your monitor may display this colour differently" disclaimer. If it's just for you own use, then you might want to invest in a huey: http://www.pantone.com/pages/products/product.aspx?pid=79 Or try and get a Pantone swatch booklet from somewhere. They're stupidly expensive for what they are though, so don't even think about buying one.