I was at a camp recently with a high level coach and he used a TBS with H3 forehand (boosted at one time, but since he coaches, he doesn't really care) and some T05 (probably old as well) on the backhand. When I grabbed his racket for blocking during one drill, I just remembered why I don't use stuff like that - the ball just kept flying off once he did a decent loop. People can block with that ALC blade and T05 rubber, I just don't happen to be one of them. Wood and ancient ESN rubber is more my kind of thing.
The coach actually agreed with my choice of equipment. He said that everyone wants to play with fast rubber because it feels good when practicing loops and you can see the ball fly, but in most matches, no one is losing because their loops are too slow, people are usually losing because their pushes and flicks are too long or they can't control the ball at 9-9 in the 5th. It's one thing if you are practicing every day like a pro and using fast equipment. It's very different when you play a lot but mostly when you can like myself. I just want something that when I spin the ball, it stays somewhere on the table and when I push the ball, it doesn't pop up when it touches my racket so I can have a chance to dig into the ball a little to add spin. I can't go to the point of tacky rubber anymore because the ball release messes up my blocking and I can't move as well as I used to, but definitely not Tenergy, where the ball is gone before I feel I had a chance to control it. Maybe T05H or Dignics would fix that, but I am not spending $100 on a rubber when I can get 4 rubbers for $120.
As for the original question on best forehand rubber, there is an argument that a forehand stroke is generally faster and harder than a backhand stroke so it is easier to use harder rubbers on the forehand. But I have explained a million times that such generalizations get people into trouble because table tennis is a very specific and subjective sport. My backhand is usually powerful enough to use what my forehand does, and I have improved my forehand a lot, but not to the point where I feel the gap to my backhand justifies a different hardness of rubber. And I know people who prefer to use softer rubber on the forehand and harder rubber on the backhand for some reason. They must have missed the memo.
And even amongst pros, Emmanuel Lebesson is still one of my idols. He is an unabashed 5 ply, soft sponge user on both sides with Tibhar FX-P and his namesake blade. He also has one of the best and most powerful forehands in the world, which you can easily see if you watch a match or two of his.
So when people talk about forehand or backhand rubber, it is better to ignore them and know what you do with your forehand or backhand and then find out about a rubber that suits that given your feeling.