Are there alternatives to Microsoft Access?

In my office, we often use MS Access for many applications (eg creating reports, data analysis and data processing) because it is convenient to use (easy data import, fast query building, easy automatization with VBA) Unfortunately, it starts to be insufficient for me due to the size limitations of the database file. This is one thing. Another thing is that Access is often unable to execute my complex SQL queries (I omit that the SQL used by Access is limited). Is anyone out there aware of any tools similar to MS Access that can be used with databases over 2GB? Possibly, I am considering using Access as a front-end, but what about the back-end? Can you recommend something?