Although I love almost any stout, a stronger indicator of my preference in a beer will be high ABV. The higher the ABV, the more I like it. I usually will drink any style of beer with the word "Imperial" on the label because they tend to have a higher ABV.
I also do not like to spend money on beer. High ABV beers tend to be more expensive. So what is the cheapest high ABV beer you know of? Over 10% is preferred, but anything over 8% will do if its cheap enough.
I remember Crucial Brew from my teenager underage drinking days and also Kestrel íBlack Caní it may have been called Kestrel Super Strength, oh they still produce the latter I have just found it see link below. I doubt that Crucial Brew is produced anymore but I suppose its equivalent would be Carlsberg Special Brew 9% and available here in the UK for £1.54 at Tesco and Sainsburys in a 500ml can if purchased in a 4 pack, its commonly regarded as the choice drink of a tramp over here, (tramp juice) but seems to be slightly better regarded than some that have been posted already.