While you are searching for the perfect sofa, one aspect you should consider is the kind of sofa back style that will fit best for your family - and the way you sit.
Tight back - If you are the kind of person who is most comfortable sitting up straight, then a tight back sofa is for you. The back is usually firm and the look is tailored and neat. Plus, there are no cushions to straighten.
Attached pillow back - If you love the look of a pillow back, but want the neatness of no loose pillows, then an attached pillow back is for you. This style sits less upright than a tight back and is a nice compromise between the tight back and the casualness of a pillow back.
Loose pillow back - If you love pillows, this style of back is for you. It has large pillows which usually have zippers so the cover can be removed and cleaned. This style can be firm or soft depending on the amount of fill in the pillow.
Multi-pillow back - This back style usually comes with more back pillows which can be arranged randomly. The pillows are softer than than the other styles and tend to be loose and overstuffed.
So are you a "lean back" or a "sit up straight" kind of person? Whichever type you are, you can find the perfect back style for you.
And if you need more help picking a sofa, I have written the Guide to Buying the Perfect Sofa. Now go out there and shop!