The first Tool album I bought was 'Undertow'.  I was pretty impressed but I wasn't in awe.  It took me nearly 6 months to get around to buy 'Aenima'.  This is singlehandedly my favorite album of all time.  Where 'Undertow'  was just an excellent alt-rock album, 'Aenima' is in a class of it's own.  It's epic, it's brilliant.  The lyrics are incredibly deep and beautiful.  The music is incredibly powerful and goes straight to your head.  Maynard's  voice is too good to be true.  I think Tool gets a bad rep because they are  usually grouped with all these lame nu-metal bands.  If you've passed up  this incredible band because of their fanbase, you're missing out.  The  lyrics are very ambiguous but the personal interpretations you can get out  of them could change your life.  Please do yourself a favor and buy one of  the best albums of the 90's if not one of the best albums ever.