A couple of friends swear by this lightweight bouncing chair from Baby Bjorn. The springlike shape means a kid can bounce himself silly with every little squirm. It's definitely the best-looking seat I've seen; it'll let you hold off the invasion of the lime green plastic furniture for another year, at least.
For some reason, the BabySitter is frequently out of stock. Right now, Baby Age has it for $84.99, which sounds like MSRP.
Got this seat to go along with the bouncing chair where the kid's heels set off a light show, as well as an Oof. We ended up retiring the other two -- at 6 mo. my son's feet were hanging off the end of both -- and now my son uses this exclusively. It's a fantastic chair. Very simple, yet it does the trick and can grow with him. Love the minimalist design.