Non-spill cups that don't spill?

[Cherrycola]

Has anyone got any recommendations for non-spill cups that actually work? We has been using a tommee tippee 'tip it up' cup but LO has worked out that if she puts her finger into the spout (it has a soft spout) the water spills out, its her new favourite game!

I bought an avent cup yesterday but its really difficult to get anything out of it (even I struggle!)

At this rate I can see me spending a fortune on cups over the next few days!