A W4 calculates how much federal tax to withhold from your paycheck each pay  period.
There are two basic drivers:  number of dependents and filing  status.
The higher the number of dependents, the less is withheld.
Married  and jointly will also have less withheld than married and seperately.
There  is really no good or bad answer, only opinion.
If you want more withheld  each pay period so that there is less of a chance of actually owing $ on  April 15th, then claim more dependents and married and jointly.
If you don't  want the government to get your $ interest free, but are aware that you may  owe $ later on (April 15th), then claim fewer dependents and married and  seperately.
I hope that made sense.
DG

Tax Question