Well - 10 years ago I was importing coffee from France, from an old artisan coffee roaster (torrefacteur, the French have a word for it, as usual) - so I learned a bit about coffee.
The best coffee I ever tasted is from Le Havre - Le Maitre - it has a picture of Joel Robuchon on the front, wearing his Culinary Condom. That is including the stuff from the Blue Mountains, and the ridiculously expensive stuff that is sourced from animal droppings.
Joel Robuchon has more Michelin stars than anybody, and is the bloke from whom Gordon Ramsay learned about being a chef (Gordon Ramsay is no.3 in the Michelin star league table).
As far as I'm concerned, Starbucks is overhyped and usually weak stuff, over the counter. The stuff they sell in IKEA is better, and you can buy a packet to take home for a sensible price - that's my value tip.
You want good instant - I buy Tchibo from Somerfields, the Columbian usually.
Starbucks are reliable, but I prefer McDonalds coffee, and it is cheaper.