Sorry, "BEST starter" can is kinda a tall order.
The problem is that they have a sharp rise in the frequency that needs a amp to work out the power. I typically say to stay away from cans that need amps if you're starting out.

I would have to agree with the above guy. A starter headphone should not pretty much require a dedicated amp and dac. However, the hd 598, from what i heard about them, sound amazing with the proper setup.

I don't agree with the other two commentators at all. Why mess around with inferior equipment? Start off with the best you can afford. At 50 ohms they're not too hard to drive and if you decide to add a headphone amp (if you hadn't bought one in the first place) things will only get better.