Rich client interactivity with JQuery etc - most robust approach?

Any views on the most robust tools to implement a pretty 'client rich' (ie charts/controls updating one another's content without postback). I have used Telerik quite a bit, but it seems very markup heavy when you want to configure it for ajax calls and controls updating each other on the client side.

The other options seem to be $ajax commands in jquery, standard updatepanels or a hybrid approach. Maintainability/simplicity is important. So is performance though - if开发者_高级运维 simple JSON can pass rather than viewstates etc, that would be preferable.

Thanks

Mark

EDIT: Thanks for the responses. The nature of my question is more around 'architecture'. In the sense of driving things from client side events (ie when dropdown A changes, use client side events to refresh the others) or using server side events to 'plumb' it all together and then render any inline javascript from that side. Hope that clarifies it a bit. Thanks

If you're looking for Free stuff;

http://www.highcharts.com/ is probably the best free jQuery charting out there. It's brilliant in what it can do.

I also use http://jqueryui.com/ for a lot of my UI needs as it contains most of the controls I use in every site I write.

jQuery has a great AJAX implementation and if you use it in conjunction with the MVC framework you have a really smooth UX.

edit

jQuery

$.get("/userControls/PrintRunPriceCalculator.ashx?pages=" + pages + "&quantity=" + quantity, {}, function (data) {
    if (data != "")
        $(".TotalAmountFigure").html(data);
});

ashx

public class PrintRunPriceCalculator : IHttpHandler, IReadOnlySessionState, IBookPrintDetail
{

    public void ProcessRequest(HttpContext context)
    {
        int quantity;
        int pages;

        try
        {
            quantity = int.Parse(context.Request.QueryString["quantity"]);
            pages = int.Parse(context.Request.QueryString["pages"]);
        }catch{ return; }

        BookPrintDetailPresenter presenter = new BookPrintDetailPresenter(this);
        context.Response.Write(presenter.GetQuote(quantity, pages));
    }

You should look past jQuery into things like backbone.js or even sproutcore.

Edit: Yeah, what you are looking for is exactly what Backbone.js does http://net.tutsplus.com/tutorials/javascript-ajax/getting-started-with-backbone-js/