To my mind, Interstellar has the best UI and price history charts.
Lupoex is also great, team is constantly improving UX and functionality.
Desktop wallet is ok for basic things, but it shows only 2 digits after decimal point in the orderbook. It also periodically throws timeout errors when order is submitted (spotted the problem more than 10 times, and I don't think that's a Horizon issue).
As far as I remember, neither of them support the orderbook price grouping which would be a great feature. I love the implementation by Poloniex, it allows you to group prices by 2, 4, and 6 digits.