Currently I'm busy with redeveloping some 'old' 2003 webparts and quite often I used a .NET datagrid to display data. Now with SharePoint 2007 we have to ability to render our data using the SPGridView. Using this control, you don't have to worry about to set CSS classes since it inherits the default SharePoint CSS so that's prety cool.
Another cool thing is that you can sort and filter like you sort and filter in SharePoint lists, although I haven't got the filtering working, the sorting is quite cool. Even more if you use the AJAX Basewebpart by .. to make it even more sexier ;)
Check out the following links that helped me these last couple of days!
Ajax thingies :