What give the smoothest top coat of paint? I have two end coats of paint applied in my living room...

I have two end coats of paint applied in my living room but I see within are still some brush lines in the paint. I would resembling a perfectly smooth paint career with no lines and I with the sole purpose have time for one final top coat. What type of tool(brush, roller,shake painter) will administer me the best finish. And I don't have a sprayer so that's not an opportunity.
Answers:    A smooth roller. One with no texture at adjectives. If you had used an alkyd paint, you would not enjoy had any lines. It is a "self-leveling" considerate of paint that resists leaving any brush or roller results.
I heard Behr is really well-mannered and probably the best one so you might want to consider that