Ratings: Tar and nicotine
Listed in increasing order
Summary tables from many countries shown below

International standards by 2002 were a limit of 15 mg/cigarette for tar and 1,3 mg/cigarette for nicotine. UK is, I think, moving to 12 mg/cigarette, and EU for 2004 is 10 mg/cigarette.  In the USA, domestic cigarettes are not limited. Some of the older brands in particular were very strong! The original Max was 3.2 mg nicotine!
In Russia, the domestic nicotine maximum is the same, but tar is 20 mg/cig. in filter cigarettes and 24 mg/cig. in cigarettes without filter. If the cigarettes are too mild, then some really interesting techniques exist.

American FTC home page for latest report on tar and nicotine:      http://www.ftc.gov/bcp/menu-tobac.htm   or
click here to download the 1998 report in PDF format. It makes a great shopping list (heh-heh). 
Czechoslovakia  click here for their report of tar and nicotine
European click here for the European report of tar and nicotine
French  click here for their report of tar and nicotine
Italian  click here for their report of tar and nicotine
Hong Kong click here for their report of tar and nicotine
UK  click here for their report of tar and nicotine
Menthol click here for a listing of USA menthol tar and nicotine

Cross reference by a list of manufacturers in the USA and their brands, and then a fairly detailed international list of brands and their manufacturer. 

European renaming - the EC has banned the use of the words 'light' 'mild' and as a consequence many or most brands have been renamed. Click here for the list from the Italians, and here for the Austrian list with more details on the renaming.