Love stock but I rather use an OEM skin.
I'm currently running sense on my H1 even though I've always liked the stock look and feel and I honestly never thought this would happen. Why is that? I feel like I would be losing too much if I switch to stock.
Browser- The H1 browser pretty much beats chrome at everything other than tab switching (its not bad but chrome's is great) I honestly dont understand why they got rid of the old browser and replaced with what seems like a beta product and thats embarrassing when you consider who is working on this thing and how long its been in the market. Samsung also has a great browser but honestly pretty much anything is better than chrome.
Camera- The ability to take video or shoot stills without switching modes is reason enough for me to stay on sense, add the attractive UI and all the features it adds (I won't elaborate on ZOEs)Samsung also has an amazing camera app that is alot more intuitive than the stock app.
Music- There is nothing wrong with the music app but extra things like fetching lyrics effortlessly and automatically is great, adjusting EQs, support for more file types. Tons of other little things like that could really make a good music app...great.
These are just examples, but if you look at pretty much any area you can see that there is alot of room for improvement. We need more things like photo spheres, features that would make us want to use stock instead of just using because it isn't bloated or butt ugly.