Top Spin is beautifully balanced between simplicity and complexity. Your array of shots consists of normal, top-spin, slice, lob and two speciality moves – the “risk” shot being the more useful of the two, it requires perfect timing and should be used sparingly.
The game's career mode is reasonably in-depth, although some players may tire of it once they achieve the rank of #1 – which doesn't take too long. The feature which really gives the game replay value, though, is its Xbox Live functionality. Part of Microsoft's XSN range of titles, Top Spin lets you find matches quickly and fairly easily. One of the only flaws in the system is the inability to play doubles matches without the teammates sharing one Xbox console.
It's the best tennis game I've played and will certainly be the standard against which future games are judged. Sega's Virtua Tennis has held that mantle for a long time but it has finally been dethroned. If you're still in doubt; Miss Kournikova does feature in the game. Go get it.