I’ve tried quite a few and only two do it for me.
The first is the Cha-Cha-Cha mentioned by @JoCat above. Currently out of stock so doesn’t help with your sale hunt but it’s brilliant. Not the most powerful vibrations but just the perfect flex, feel and penetrating vibes to hit the spot perfectly for me. My full review can be found here if you want a read.
The second is the Joy Roller, which is very different but very powerful and a great shape to hold and use. Looks a bit odd with the massager on it but it’s so effective to use. Also, is on sale, albeit not with a huge discount. Full review here.
Long list of ones that don’t work for me too, but the two above are both great.