Loose whole leaf tea is worth the cash. If you're making green or oolong, you can use the leaves a few times, sometimes with better results each time.
This comes from a... basically a tea textbook that a friend of mine has. For temperatures:
White tea, Japanese green tea, and many new or spring green teas: 71-77c.
Green tea (standard): "Column of steam steadily rising" 77-82c.
Oolong tea: "Fish eyes" 82-93c.
Black tea: "String of pearls" 88-93c.
Pu-erh tea: "Turbulent waters" 93-100c.
The fish eyes/string of pearls/turbulent waters thing refers to what the bubbles look like if you haven't got a thermometer. If you have one or care to buy one, use a digital thermometer. There's a range, usually of 5-10 degrees, in which flavors are released, but bitter tannins are not. It makes a HUGE difference.
For times:
Black tea: 3-5 minutes (one steeping only)
Oolong tea: 90 seconds to 2 minutes (several steepings)
Green tea: 2-3 minutes (several steepings)
Spring (or new) green tea: 90 seconds to 2 minutes (several steepings)
White tea: 90 seconds to 2 minutes (several steepings)
Pu-erh tea: 2-5 minutes (many steepings)
Don't think I've ever had a pu-erh tea.
It's worth googling around for ratios of tea to water, if it's not listed by the specific tea. Generally, oolong takes about twice as much as other teas. It might be what you're after, if you're looking for something with a strong flavor that works well with some sweetness.
My own favourite tea ever is lapsang souchong, which is a smoked black tea.