My favorite teas:
Leaf-brewed Darjeeling, occasionally with a drop of lemon. If you're ever in West Bengal, try to get some Darjeeling tea straight from the gardens... they're unmixed and make you rethink your conception of what tea is.... Assam teas are also nice.
Earl Grey blends (various Indian black teas) are alright... get boring after a while...
Dhaabaa (roadside food-stands or mini-restaurants) chai... the kind you get on the streets in India, where they have a huge vat of boiling milk with tea-leaf dross caking the bottom and sides, re-boiling and re-boiling, throwing in a couple of teaspoons of sugar occasionally... it comes out like a dream.... no 'chai tea' in the world can match a road-side Indian chai. Add ginger and a little masala if desired.
[Just wanted to point out something: "chai tea" is redundant... that's saying 'tea tea'.]
Leaf-brewed green tea.
A great tea-bag variety is Wagh-Bakri (Tiger & Goat)... masala chai... for when I don't feel like brewing...
Lipton is balls.
Some of the herbal teas are nice once in a while... but the flavorings can be grating.