standalone database
Your options are:
- Sqlite
- Firebird
- Sql Server CE - depricated, latest version, 4.0 SP1 was released 8/31/2012
- VistaDB - commercial
- ESE - Which is hard to integrate with .Net
SQL CE and Firebird are a lot faster when you need multithreaded writes, sqlite is king for single threaded access, or multithreaded reads. VistaDb is 100% managed so you can ship it on embedded devices.
These DBs in general will give you better reliability and performance to access. I would strongly recommend against using any of these dbs over a network share.
Yes. I would recommend System.Data.SQLite, which is a ADO.NET wrapper around SQLite, a popular embedded database written in C.