Wii sports makes for a great title to show off the intuitive Wii controls.
The downside of Wii Sports isn't the graphics, although a bit dated, they do just fine and your own created Mii fits like a glove in the setting. The problem with Wii Sports is the motion sensing capabilities which can in fact be reduced to just tiny wiggling with the remote. Sure tennis is most fun when trying to actually swing with the remote, but the game dosen't force you to do it. In other Wii titles this can be a good thing. In Wii sports where the feeling of the sports and the fabulous Wii controls are the foundation, it can throw you a bit off balance.
Considering Wii Sports is packed in with the Wii console itself it makes for great fun whitout costing any extra money. This is a great game that you can take out and play no matter what guests you have!