Fixed rate ISAs (for one year are currently around 4 / 4.5% - lower (which is clearly not normal, but rates are expected to fall) if you fix for two years.
I've earnt slightly more than that this year on PBs, without any 'big' wins - maybe we've just been lucky.
Interesting that you say that it beats what you'd get on (for example) an ISA or one year fixed rate bond.
Some of those quoting their monthly winnings above, I would guess have £50K of bonds.
If you have £50k of premium bonds, you'd have to win approx. £230.00 a month to keep up with an ISA...