Black Adder - The Complete Black Adder Reviews
Blackadder II is one of the finest sitcoms ever. So incredibly smart and brilliantly written. Utterly amazing.
Blackadder the Third is like Blackadder II watered down. Still VERY funny, but not quite as good a setting.
Blackadder Goes Forth just never really worked for me like the other series do. It is funny, but just not Blackadder quality.
The complete set is all of the above and the awesome Blackadder's Christmas Carol and the fairly decent Blackadder Back & Forth.