Double Dash, in my opinion, is the best in the Mario Kart series.
The controls at first can be difficult to get used too, but after some practice you get the hang of it. There are different levels of difficulty, with mirror being the hardest, and you will spend many hours trying to get a gold trophy in each cup. Even though i've had it for years, i still find myself playing it without getting bored because each course is different and a challenge. The music goes well with each course, you can pick from many different characters and each of them have a special "item" that they can get, that is unique only to them. Furthermore, you can pick your own kart, and throughout the game you'll unlock more karts and more characters. Overall, this game was a whole lot of fun to play for me and I feel that GameSpot rated it a bit low.