Today this does not exist. There are products like the ones you mentioned that you tried, but in my experience none of them will make an experienced Excel user happy.
My company is creating Excel compatible spreadsheet components for use with Windows Forms and ASP.NET. We asked this question for many years, so we, of course, considered it one, because it looks like a good business. But HTML / JavaScript is simply not the right platform for creating something that "feels right" for users who want it to work like Excel - IMO.
We focused on the idea of building a spreadsheet management for Silverlight. I believe that this will give you the best of both worlds - an interactive spreadsheet with a cross-platform browser, which will be convenient for any Excel user. Unfortunately, this will not happen this month or next ...
In my previous company, we actually created the spreadsheet component as a Netscape plugin, as an ActiveX control, and as a Java applet. They had little success, but none of these technologies has ever become ubiquitous in the enterprise for various reasons. I believe that Microsoft will finally get through Silverlight and that Silverlight will become the gold standard for browser-based business applications.
EDIT:
I should have mentioned that the product mentioned above is Formula One / NET (Netscape Plugin released ~ 1995), Formula One / ActiveX and Formula One for Java, which Actuate now sells as e.Spreadsheet. I quit in 2002, but AFAIK they still support the Java applet, which is probably the best example of such an Excel as the user interface in the browser (I am no longer interested in this product - in fact, we are to some extent competing with e.Spreadsheet and intend to get a better answer with the Silverlight control in the future). I did not mention this by name in my original answer because it is a Java product and not a .NET product, but it is a potential answer even for an ASP.NET website.
Lloyd Cotten correctly comments that Google Docs is an example of a spreadsheet built using HTML / JavaScript. Lloyd says Google Docs "definitely" feels good "in its resemblance to Excel." Although I respect Lloyd’s opinion, in my experience, Google Docs doesn’t "feel good." Perhaps this is because I'm the guy from the spreadsheet. I know that we talk with potential customers almost every day, who try to solve the OP problem, and they all look and cannot find the one they are satisfied with - but, of course, they will not call us if they have this dealing with a biased model, and I understand that.
So I just want to make it clear that there are actually many examples of grids and HTML / JavaScript tables that can be used. It’s just that I don’t want to use them, because I expect some keys to do certain things and a certain level of responsiveness that I don’t have today, with any of the HTML / JavaScript solutions I tried (and I look at them regularly , because my company could definitely sell such a product, if it were possible to build one that we could be proud of).