1, Law Reports (1865-) (preferred cite for cases after 1864)
2, All England Law Reports
WestlawNext has an United Kingdom case law database; coverage begins in 1865, with a few cases going back as far 1220. To get to this database, from the home page-->International Materials-->United Kingdom-->United Kingdom Cases. There may be analysis, but not full text, for some cases. For those cases, use ICLR.
The Incorporated Council of Law Reporting, ICLR is a legal charity, set up in 1865. We publish law reports of the judicial decisions of the Superior and Appellate Courts in England and Wales. Following Lord Woolf's Practice Direction 2001: “For the avoidance of doubt, the ICLR official Law Reports should be cited in preference to any other series. Other series of reports may only be used when a case is not reported in the Law Reports.”