In any city, click on 'fight' look to the right of the screen where your defense items are pictured, Those are your top 3 items. You can hover over them for their names.
As far as I know, you can't get a complete list of all defense items used while fighting. You can however see your attack items used by choosing :show all items used" after you win or lose a fight.
- There is no way to see your defense items in Mafia Wars itself. But you can use the bookmarklet from Blofeld's Loot List & Combat Calculator: