Assume you have a customer-facing application hosted on a Web server. You have no control or knowledge of the customer's client. You also want an appealing design but you don't want to overwhelm the user with heavy graphics and/or obtrusive JavaScript.
You've got a nice CSS layout with rounded corners but the default gray buttons stand out like a sore thumb.
I can search the Internet for examples like this, but I see nothing that helps me determine whether or not a given solution is appropriate or if a better one exists.
With that in mind, what are your top suggestions for creating attractive / usable buttons in HTML that work or at least degrade gracefully among the various browsers / platforms?