i use Douwe Egberts Continental Dark Gold (it's called something along those lines anyway). However, I recommend you splash out on a filter coffee maker (as cheap as a tenner these days).
You can also get coffee bags, like tea bags but with filter coffee in them. I tend to use 2 right enough so would be costly if you drink loads of coffee (think they are around �1.90 for 18 bags). But they are quite convenient.
Kenco blue is OK, but have to agree with the others, instant coffee is pretty awful. get yourself a cafetiere and open up a whole new world of delicious coffee.................maybe even get a bean grinder too?
For me, Douwe Egberts Continental Gold is very nice but I've since discovered that Marks & Spencers Italian is really very good too - both remind me of those strong coffees you get while on your holiday - yumma