As a shareholder, which would you rather have?

If you ignore taxes it really doesn't matter. Buybacks should be made at attractive prices and not used to pay for employee stock options (dilution).

It's hard to ignore taxes though. They count.
Other. If the company is great buybacks are the best second to reinvesting in the company. Then dividends. For a par subpar company with low ROIC dividends are best because the company can't do much better with the cash itself. I'm inbetween though overall. I'm skeptical of most managers so in that case, dividends.
buybacks