which control better to use?

Hi,
 Practically it will always been difficult to say which control is better, as suthish said might be your data binding rate is at high stage. 
 theoretically i can tell you something which will be helpful for you :
   1.Many make a blind choice of choosing datagrid directly , but that's not the right way. Datagrid provides ability to allow the end-user to sort, page, and edit its data.But it comes at a cost of speed.Second the display format is simple that is in row and columns. 
   2.Real life scenarios can be more demanding that With its templates, the DataList provides more control over the look and feel of the displayed data than the DataGrid.It offers better performance than datagrid.
 3.Repeater control allows for complete and total control. With the Repeater, the only HTML emitted are the values of the databinding statements in the templates along with the HTML markup specified in the templates—no "extra" HTML is emitted, as with the DataGrid and DataList. By requiring the developer to specify the complete generated HTML markup, the Repeater often requires the longest development time.But repeater does not provide editing features like datagrid so everything has to be coded by programmer . However, the Repeater does boast the best performance of the three data Web controls. Repeater is fastest followed by Datalist and finally datagrid.