Scottish Slimmers is the easiest it's just basically calorie counting using their check system (25 cals = 1 check).
You get a check allowance for your weight plus a dairy and fruit allowance each day. The check allowance decreases as you lose weight. No complicated points/syns to work out. No banned foods.
The online service is very basic, no food trackers/diaries. You are better off buying the books online and taking the E-support if you want to use the forums.
Never done WW but my sister does and struggles with it sometimes and has been stuck at the same weight for ages now.