Maybe a 2 part question is more appropriate. What coffee do you prefer and what roast degree? See the roasts are to draw out the characteristics we are trying to showcase in that bean. I personally am loving a SO. Ethiopian Yirgacheffee from www.highmule.com, roasted to medium roast. Notes : Grapefruit, white peach, and honey.
For some time I've been really digging dry processed anything... currently have a killer Brazil that excels even as a single origin. I say that as I strongly prefer a quality blend over pretty much any single origin, but just how I roll. I do have one blend in my stash year round when possible as it's a mix of all dry processed offerings from Yemen, Brazil and Ethiopia. If I had to pick one green to roast the rest of my life that'd be it as for my preferred taste/texture in espresso nothing has beaten it yet.
This is an individual question with no real answer.
Personally, I prefer Indonesian coffees (not Sumatra, but Flores and similar) or lesser known African coffees from Uganda or D.R. Congo when I can get them. I also prefer roasts of City+ or occasionally Full City.
That probably doesn't help you, but you asked.
When you start, be like a young man on the dating scene for the first time.... play the field.
I tried pretty much the full spectrum. I developed a fondness for the Panama Geisha beans, Ethiopia, Kenya and Brazil beans. I tried a lot of the expensive "blue chip beans" (three types of Kona, Jamaica Blue Mountain, etc...) and I really liked them. But, in terms of bang for the buck, I would rather have 4 times the quantity of some other types of beans.
Tonight I am relaxing with a Rwanda bean. It has no amazing characteristics, but it is just a solid coffee. No matter what you find, every now and then you will want to "recalibrate" with a GOOD basic cup... It helps you appreciate some of the more exotic flavors which can be found in other beans.