what does he/she like?
If she likes music, buy her the newest CD by her favorite artist. If she loves bubble baths, take the kids out for an hour, prepare the bathroom with bath salts, a decorative candle, and she will be eternally grateful.
A gift certificate for a pedicure (trust me, that is the best gift ever !!)
Get a baby sitter for an hour a week, for a month, and just go on a walk together.
Most women want one thing from their spouse, a gift that shows he pays attention to what is important to her – and it usually cost little or nothing.
Regarding gifts to husbands, I find that a tougher problem, because my husband is so easygoing and comfortable with whatever he has or whatever happens, that there is little he wants or needs.