I keep coming back to M-Power / Nemesis Super and Solutions Cornwall Heavy Duty.
However, Chemspec DFC210 and Prochem Double Clean are also in this "safe" zone.
I am getting used to Prochem Powerburst now but cant use the same expressions as others as I dont particularly see a Wow factor (hate that word on those house programs on telly - Wow. So false).
I have Prochem Ultra Pack Renovate for draft marks and soot type stuff, and used Champion for that too with good effect, and also Solutions Heavy Duty as mentioned before.