Just get the Black Sabbath/Ozzy album with it. It rocks and includes more songs that rock.
As do all of the Ozzy era Sabbath albums. The last two, Technical Ecstasy and Never Say Die are a bit weak, but still have some good stuff. If you enjoy Paranoid (the album w/ Iron Man on it), I would definitely recommend the rest of the 70s stuff :
Master of Reality (often seen as the album that started heavy metal, as the band tuned down a step and a half to C#)
Sabbath Bloody Sabbath (a bit more progressive, spacey stuff on here like 'Spiral Architect')
Vol. 4 (lots of heavy guitar riffs. includes a thank-you to Coke-a-Cola, as they were doing a lot of drugs by this point)
Sabotage (a few of their heaviest songs on here... the first three are killer)
Black Sabbath (the debut. a bit more heavy 60s rock style, but the devil themes were a novelty at the time.)
The Ozzy lineup also has a great live album from '97 or '98 called Reunion. It's great stuff if you want to hear the old songs without the dated production of the old studio albums. It was the album that got me into heavy metal - and older rock bands in general.
If you're interested in hearing what the band sounds like today - with their second vocalist, who's keen on D&D lyrics and the like - you can check out an official stream of the new album from VH1 here:
http://www.vh1.com/artists/az/heaven_and_hell/2424995/album.jhtml?popThis=playIt()