...this is very personal, for me the great brands are : Rolex, Patek, AP, Lange, Vacheron, Breguet ( even if i am not a fan of VC and breguet )
The following brands have the potential to join the club, but IMO they are underdogs :
1- FP journe, the most under rated watchmaker IMO. I think its a matter of time before he gets the recognition he deserves.
2- JLC right at the door but never seems to cross the entry. Doing great movements, maybe the best in research, inovations,etc... but unfortunatly there is always something wrong or missing that prevents me from pulling the trigger on a watch i like. Even if they deserves the top podium on the very high complication.
3- Cartier is boosting its watch department. New manufacture, new in-house movements, big marketing and belongs to a strong group ( Richemont ). Plus it has a history, if i am not wrong, they invented the wrist watch. But the jewelry tag on it can be viewed as a burden for many horology lovers.
4- Hublot is seriously booming since 3-4 years. Now more than ever, they are doing their inhouse movements, and especially the high end complications since they "swallowed" BNB. Top management leading it ( J-C Biver ) and huge group behind them, LVMH (helps in opening a boutique in Place Vendome in Paris, right next to Patek Philippe ) 
Still, it will always feel like an underdog of AP and plumbed by the zillion Limited editions they've made. They boxe in the same category as Richard Mille ( but with a little more credibility ) Too much marketing and trendy, but sooner or later, people wake up.
To conclude, i see marketing boost on brands, but i don't see anybody coming close to the great brands, but those above are the closest 