How do you people get attacked before you get to level two? I get evasion first, then one of the other two! Evasion is good for a first skill, even against the "green" creeps it can save 100+ health, without costing any mana - and by the time you have a DH, you should have two archers (thats what i have, anyway) which means you can creep easy greens, getting you to level two! After that its immolation (for killing tier one units) or mana burn (which isnt as effective as you make it out to be, anyway), depending on what i feel like
my typical: eva/imo/eva/mb/eva/meta/mb*2/imo*2
This gives you an effective low level killer, and imo isnt worth it more than once