This is really easy to do if you use SharePoint Designer. The scenario here is that I have a custom list and I want to remove the actions menu.
Before customisation:

Steps:
- Open the site in SharePoint designer and then navigate to the AllItems.aspx form for your list, mine was at Lists/Test/AllItems.aspx
- Right click on the Allitems.aspx form and select 'New from existing page'. We do this as it's not a good idea to customise a page from its site definition. Save the file as AllItems2.aspx
- In the AllItems2.aspx form right click the list web part and select Convert to XSLT data view. This allows much more control and opportunity to customise the look and feel of the list.
- Now simply delete the unwanted actions menu and save the page. At this point it's a good idea to view it in the browser and see how it looks. You will notice some slight differences after the conversion to Data View Web Part.
- When you're happy with the new form you can delete the old AllItems.aspx. We don't want people to still be able to navigate to this page.
- The List will now default to displaying your new AllItems2.aspx page (minus the action menu). I renamed the page back to AllItems.aspx for consistency.
After customisation:
