football matter /playing time
Chelsea > United > City
he's looking for no 10 role.
Chelsea currently looking to overhaul his squad. so there's vacancy on forwards role. but without manager (i take it RDM is uncertain) how can Hazard be sure he's on manager's plan?
United got numbers of forwards, but player of his quality could easily slot in and dispose others.
in City, he need to compete with at least 2 superior players in Silva, Nasri (which i think have similar attributes /positions /role). but City got a best team, so silverware prospects are better.

financial matter /wages /repay Lille /self marketability
City > Chelsea > United
its obvious. but at this point, its said Hazard was agreed to all 3 packages deal. on sidenote, United are far more marketable club, so Hazard have better financial prospect for his own lucrative sponsorship /endorsement. plus, United using Nike (same as Hazard)

management stability /tradition
United > Chelsea > City
SAF is known for man management and handling the youngsters, and his future are more than secured. RDM future are questionable, so Hazard signing will be rather club's /RA's signing than manager's signing. RM future seem secured for another season as long as he deliver.