I would recommend BLToolkit (and the newer lighter version Linq2Db -- not to be confused with Linq to SQL). You keep an abstraction level above raw SQL via LINQ

I would recommend BLToolkit (and the newer lighter version Linq2Db -- not to be confused with Linq to SQL). You keep an abstraction level above raw SQL via LINQ and with multiple DB providers you can easily switch between databases without rewriting your queries (provided you don't use any DB-specific features).