There is so much choice out there, so for my part, I first bought an expensive Paramo Alta 2 (£250) which I find, too heavy, too hot in the warmer months and I got fed up with the difficulty of folding it down to a reasonable rucksack storage size and for me, its material is just too slippery.
Then I went to the other extreme, I bought a less than £20 Champion waterproof long coat and then a less than £20 Champion waterproof standard length jacket, and in my opinion, both are as good as my Paramo. If they have a fault it's because they would not be seen as stylish and of course, they are cheap! I used both for well over a year and never had any problems in them keeping me dry, their hoods are rather good as well. The Champions are single skin and their main drawback for me, like the Paramo, is that when exerting myself, they like so many other jackets can suffer from inside perspiration. Easily solved though, I just opened the full zip and the air dries my torso area easily.
I really wanted to buy a long waterproof coat (down to my mid-calf) made of a different waterproof material but I couldn't find anything like this so in the end, I accepted my lot and knew I had to go for a bum length jacket or get nothing at all.
I also owned a Marmot Precip, again a single skin, which I liked a lot but it to when exerting myself could feel damp and clammy against bare skin, like my arms.
Personally, I liked the look of the Alpkit Gravitas, its a 3 layer, not a 2.5 and I read some good write-ups and saw some equally good YouTube videos about it. I didn't buy it in the end, the lure of a Rab bargain swayed me, so I've just bought their Rab Kinetic hoody Version 2.0 at a pleasantly low price. It hasn't experienced rain yet but it feels lovely and cosy to wear, no rustling noises and its light in weight.
I wish you luck.