Million of them when I google but nothing really clear or enlarges well. Would prefer a map with english soi names, BTS, rail. Downloadable great in high res showing main tourist spots from Main central area (Chinatown, Silom etc) to Suk

That's a lot of detail to expect on a relatively small computer screen. If you zoom in you lose perspective and if you zoom out you lose the detail.

The best map I've ever had (and still use) is an old fashioned foldout paper map produced by GeoCenter. There's supposed to be an updated version available soon. Online maps are not necessarily any more up to date and many are far less accurate.

There are probably other good maps available in local bookstores (along with others that are pretty useless).

There are a bunch out there. Here's a few I've used in the past:

http://www.bangkok-maps.com/bts.htm

http://www.bts.co.th/customer/en/main.aspx