I have 3 different W-2s that I am entering into Turbo Tax. On the first two, line 15 has my state (Washington) and Line 16 shows the same amount as line 1. However on my 3rd W-2 Line 15 has WA and line 16 is blank? Is this right? I am only asking because after I enter this last W-2 I go from a decent return to owing just over $1000 and this is the only part I notice that is different.

If line 16 is blank that means that you had no income that is taxable by WA. Since WA has no income tax, perhaps the issuer of that particular W2 just didn't bother putting a number there.

But it shouldn't matter. For your federal return the important figures from your W2 are lines 1 and 2, as they show your wages and how much federal tax was withheld, and also line 17 if you lived in a state with income tax. For this third W2 perhaps the entry on line 2 was too little?