Every kitchen I've had as an adult has had an island. Kitchen islands are often a wonderful design feature but they are often not properly thought out and stuck in a kitchen as an afterthought. If your kitchen is big enough, adding an island can give your kitchen an extra counter space boost.
What is necessary for a good kitchen island?
If it was left up to my 9 year old, he would no doubt design something like this.
First off size. A good island is at least least 4 feet long and 2 1/2 feet wide and has clearance of at least 3 feet all around. Sinks should have at least 18" on either side. You should also be able to wipe off an island without having to climb on it. Yes some islands are too deep.
My current kitchen island was a fail in that department because the edge of the shink was only about 4". You can see it a bit in this VERY messy picture.
I am a firm believer that every kitchen island should have one of these.
Its a simple thing that improves functionality in huge ways.
Lighting is also critical to a good island. Overhead is often best.
Islands can be pretty and functional without a sink. Often times, like my old island, it would be more functional without a sink.
When thinking about a kicthen island you should ponder these questions.
Do you require some sort of seating?
Do you have enough space for an island? Sexy as a kitchen island is, often they are squeezed into kitchens that lack the proper space.
What is the general function your looking for? Seating? Food prep? Homework?
By replacing the counter and moving a set of drawers we were able to take our builder kitchen from dysfunctional and borning to highly functional workhorse. It is now the favorite place to sit and do homework thanks to that ever important new electrical outlet that welcomes the kids laptops.