A plain text based database
I'm no huge fan of Microsoft Access, but I'd be curious to know why you were unsuccessful at it.  It should easily be able to hold that information and is probably easier to learn than other RDBMS systems.
Having said that, I think either MySql or Sql Server Express would work great.  You would use a text import process (Sql Server has a wizard that makes it easy), bring all the data into one table and then dedup and organize anyway you see fit.  

1 million rows with 10 columns wont be a very large table, my guess is it will be somewhere near 500Mb.