The company doing the best with just tripling earnings is Dollar General Stores. 8300 stores.The only problem is they are owned by privately held KKR Kohlberg Kravis, & Roberts. You can purchase on the Euronext Amsterdam exchange, (symbol KKR) for $8.96 cents a share. That symbol represents a 30% interest in KKR and its whole porfolfio of 49 companies, so that is pretty diluted ownership of the "dollar store".
Over a three year period your best bet would have been to own Dollar Tree , (symbol DLTR). It has been up 47% over that period. This one would be the best long term investment for an IRA account. 99 Cents stores , (symbol NDN) , would have had you up 9.6% over the last 3 years. Family Dollar Stores , (symbol FDO), is down <-3.9%> over the last three years, but that was mostly because of a last quarter miss on earnings and downdraft of the stock. This investment may be the best from a value purchase standpoint, with decent earnings per share, ($2.02 in 2009/$2.26 in 2010 forecast) and pretty good growth , 12-13% projected sales growth. So if your not spending your $1.00 on a lottery ticket, go and buy something at your local 5 & 10 store . One worth a visit is the Jolly Trolley store, in sunny Dushore, PA. It is at the corner where the only stop light exist in Sullivan County, PA.