Mercury Meltdown Revolution (MMR) is a great little game for Wii that's available at a budget price. Think of it as a cross between Marble Madness and Monkey Ball. While garbage like Boogie and licensed dreck sell like hotcakes, games like MMR go unnoticed and unappreciated. You can help remedy that by snagging yourself a copy of MMR for the low price of $19.99 from Buy.com.
If you use Google Checkout as a first-time customer, you get $10 off. So with that discount, my copy of MMR came to just under $15 shipped - plus it arrived only 2 days later. You can't beat a deal like that, so check it out.