Especially to Bach newcomers, I would recommend the Brandenburg concertos and orchestral suites. I love the performance by Trevor Pinnock / The English Concert: http://www.amazon.com/Bach-Brandenburg-Concertos-Orchestral-...
My favorite Bach recording has to be Glenn Gould's The Art of Fugue (but it is perhaps not as accessible).
The Mass in B minor is also incredible (don't have a specific recording to point to there).