Morning - Assam, sometimes with milk and sugar, sometimes black
On a Sunday morning, Earl Grey
Afternoon - Ceylon black tea or darjeeling. Sometimes when I'm in the mood, a chai tea (unfortunately I've not had the pleasure of trying a real masala chai)
Evening - Lapsang Souchong sometimes Jasmine tea (not tried as much as I'd like, tends to be hit and miss)
With a meal (or any time of day actually) - green tea, sencha when I feel like a change, otherwise just gunpowder.
Tea to avoid - almost anything that is blended, anything flavoured and anything British that isn't Twinings
I've tried a few others and not found any of them particularly special. I tend to stick with what I know. The best tea I've ever had by far was some brought back from China. It wasn't expensive, just some low grade green tea from a market; and it still tasted way better than anything else I've ever tried.