#4 Paris Saint-Germain

Like Manchester United, the French club has been chasing after Ronaldo for quite a while now. Especially last summer the transfer appeared to be sealed when the Portuguese international apparently met with club boss Nasser Al-Khalaifi.
The record-breaking signing of Neymar last summer could have signalled the end of the Parisians' pursuit of Ronaldo, although recent reports claim that PSG still has a firm interest in acquiring their long-time transfer target.
PSG would arguably be prepared to offer Ronaldo the largest paycheck, a factor that is not to be under-estimated when facing retirement. Despite his brands running well at the moment, the Portuguese could still be tempted to milk the Parisian cash cow.