I only use tea bags when I don't have access to equipment to brew loose, and have found that tea bags are generally only good for a singe use. I bought a Mrs. Tea hot tea maker recently, and love it -- you put the loose tea into the brew basket filter, adjust for the darkness you desire, and it brews into a ceramic teapot that can be used for serving, as it comes with a matching lid. They apparently aren't made anymore (??) but you can still purchase them on eBay. If you're a regular tea drinker who enjoys having more than one cup at a time, I recommend it for its ease of use, quick cleanup, and quality of tea produced.
Just a reminder regarding adding milk products to your tea, if you drink it for health reasons: the caseins in milk have been found to reduce the beneficial vasodilation effects of black tea. Here's an article for more info:
BBC NEWS | Health | Milk in tea 'blocks health gains'.
Importantly, the article does state that milk hasn't been shown to affect the other health benefits of drinking tea.