Of course, when asking the question, I had one site particularly in mind.

ABC Alphabet and Phonemic awareness has a really good series of presentations of each letter, with little animations, some puzzles.

My eldest has liked that site since she was about two and a half - she's nearly 5 now, and still likes it (especially now she can work the mouse on her own).

We adore

Mr Picassohead when we are feeling creative and up for producing some artwork (that can also double up as a great gift, because you get to sign you picture and either print it or send it by mail to the recipient/recipients of your choice.

We also like Up to ten a bilingual fun games and leaning site for ages 1 through to 10.

This Cook a chili for Boowa and Kwala is funny more than educational but I do recommend it nevertheless.

Here's another one for learning to recognise animal sounds:

Jay calls