I drink tea over coffee (for digestive reasons), and I assume I am missing out on really good tea. Any readily-available loose-leaf tea recommendations?
For Chinese teas easily found in the US, dragon well (longjing) and iron buddha (tie guan yin) are very drinkable green teas. Iron Buddha tends to taste a bit more metallic, leafy, and sweet, Dragon Well tends to have a warmer flavor with a tiny hint of savoriness. Both are much lighter in flavor than, say, Earl Grey, which makes them very drinkable even in large quantities, but if you're used to Earl Grey you might not be able to taste these teas. If you want a stronger, more earthy, less leafy flavor, you can find puerh fairly easily. There's a very large range of quality for puerh, so this can be a rabbit hole. As a general rule, you should only buy loose leaf for Chinese tea varieties. I've had dragon well in a bag/sachet before and it tastes like a poor facsimile.
I specifically didn't mention Jasmine because Jasmine tea is often a lower grade of quality in the US, which has the downside of tasting too leafy/bitter/heavy on tannin. If you find a higher quality loose leaf Jasmine, it's also a very drinkable tea that you might like.
In general, I personally prefer leaf-only-no-added-flavors teas, but everyone's tastes differ. What I recommend to everyone who asks is to try a lot of varieties from different countries (mainly China, Japan, India, and try white, green, red, and black varieties), try a few of the flowery/herbal/fruity blends, and settle on whatever you like.