I think the leap Frog toys are totally worth it, but you can get them used on CL or at rummage sales. The Leap Frog Fridge Phonics taught my 2 year old the alphabet in under a month - sometimes kids learn better from toys than from moms. Love the musical caterpillar too. My older son played with the Leap Frog steering wheel every single day from 10 months old until around 3 1/2; my younger one is not really into that one. The Fridge Farm is cute and funny. I love the fridge toys since they can play in the kitchen while you make dinner.
I also agree with everything else said except about the Leap Frog toys.
Oh!! Little People Town. Not sure the exact name, but it's a fold-able learning town. My 4 year old and 1 year old play with it side by side. Also, the Little People A to Z zoo is great.
Also, the Melissa and Doug toys. The puzzles, cutting food, everything they make is awesome!