Vast and growing collection of indexed parish register material, including some which are digitised. Some digitised registers can be viewed on any computer, others can only be seen at a FamilySearch Center, (or with and LDS account) depending on the licensing arrangement with the authority which holds the original registers. There are lists of databases of all kinds (not just parish registers) at the bottom of the search pages for England and Wales.
Lots of index-only records, many of which are also on FamilySearch. Unique digitised and index collections including the following areas:
London/Middlesex (not including Westminster)
It is also worth searching Google Books and The Internet Archive for printed registers, such as Phillimore's Marriages, and publications of various Record Societies. The entries are mainly dated 1812 and earlier.