I have a hard time recommending either.
The Ti4400 was my favorite of the GF4 line before the prices on the 4600's came down. In a lot of cases the 4600 is now only $20 more expensive, so the 4400 has become the answer to a question that no one remembers.
The 8500 isn't in the 4400/4600 league when it comes to performance. Its still fast enough to run anything you want to throw at it at up to 1024x768, but if you want to run newer games like UT 2K3 at 1280x1024, you want something with a little more horsepower than the 8500.
(And I'm presuming that you weren't talking about the 8500AIW. If you were, don't. That's a horribly overpriced card for what you get. Buying the card you need for gaming and then adding in a seperate $50-80 TV tuner is a much smarter investment.)
Back to the videocard, in the $200-250 range that you are talking about, I'm recommending waiting to see how ATI prices the Radeon 9500 and 9500 Pro. If ATI goes for the throat and pits the 9500 Pro directly against the Ti4600 at $250, that will be the the video card deal of the fourth quarter. That's not a lock, there is a good chance the Pro will come in at $280-300 while the base 9500 will take on the 4600 in a pretty evenly matched fight, but the possibility of getting a 9500 Pro for what you'd pay for a 4600 is worth waiting for.
BHD