It may not be fancy, but the Playskool Shape Sorter does a great job when it comes to teaching toddlers.
On the left of the sorter there is a triangle oval and semi-circle with raised dots for texture around the shapes. This exact shapes and pattern can be found on the right side of the sorter as well. The front of the sorter has a diamond, square and rectangle with raised triangle pattern surrounding the shapes. This pattern and shapes can be found on the back of the sorter. Do you see a pattern here? The lid is a bit tricky for smaller ones but raises easily for adults and older children. This lid can also be taken off of the hinges so that younger children can play with out so much confusion.