Only 3? Very difficult and unfair. I guess it would be:
1. Mahler Symphony no.2, probably the Bernstein version, though on SACD it would be Litton/DSO or Tilson-Thomas/SFO
2. Bach--Brandenbergs, as Warren--probably Pinnock's version. Always need Bach.
3. Durufle and Faure Requiems (Shaw's old Telarc version, which has both of them).
This list could change daily, of course.