Well to me there is nothing that is a deal breaker apart from Nokia Drive, but I heard that they were implanting to all WP8 devices..
There is also a better ESPN app but again... not so exclusive... nothing that is a deal breaker, in fact if you had to choose a device only because of it's apps, then Windows Phone would be a terrible choice.
Have to say I don't have time to type them all but it seems a trend right now that Nokia are bringing free game apps to the Lumia line. While others have to pay for the games. BUT the free Nokia ones aren't Xbox live points giving. Outside of games I use and really enjoy this city lens app. Its awesome when your looking for a new place to eat
Drive is now on all WP8. Its all down to you. As someone has already said if its apps your after WP8 isn't the choice for you. I have a Lumia 920 and I really like it. Nokia are providing alot of support to WP but that doesn't mean it will be the right phone for you.