Congrats on the lucky find. I hope you enjoy =)
I think the first week or two I felt goofy playing Wii Sports..but once you get over the "I'm too cool to look silly" mindset and let yourself enjoy it (because it really is a lot of fun) you won't regret it. A lot of the hatred for the Wii stems from people who think themselves too cool to look a little silly. Personally I found it to be a great stress reliever because it helps you not take yourself so seriously all the time.
To borrow a line:
I'll see if anyone can name the source of that quote, more details on the source = more credit =)
PS - I highly recommend you follow the advise of those pointing out GC games you might have missed...that is assuming you haven't played them already. And specifically Pikmin 1 and Pikmin 2 (play 1 then 2, its hard to explain why but just trust me).