MS SQL 2005 / 2008 WorkGroup Edition (better than SQL Express) with:
- No limits on number of databases or database size (except for Unlimited)
- MS SQL Fulltext Search
- ASP.NET SQL Server Session Support
- SQL 2005 Reporting Services Hosting
- ADO
- ADO.NET
- OLEDB
- MDAC 2.8
- SQLXML 4.0
- SQL Native client