Who is more powerful, The Spectre or The Living Tribunal?
Without a doubt, the Living Tribunal is significantly more powerful than the Specter. Their spheres of influence are quite different, where the Living Tribunal adjudicates over issues of Universal or even Multiversal import, the Specter is more concerned with Earthly concerns, though can and will act against greater threats if he is needed to do so.
If we are using both of them at their peak potential, Spectre is more powerful
If we rank them more consistently Living Tribunal is more Powerful
Living Tribunal has been more consistent throughout his journey while spectre has been heavily inconsistent
But if we are talking about their full potential, spectre is more powerful due to following reasons.....
Spectre is Multiversal++++++++++++ at his peak
He was re-creating entire DC Multiverse by just 0.01% of his power
This is very hard to answer. The spectre is the embodiment of The Presence's vengence, while the living tribunal is the being who was in charge of the Marvel multiverse under TOAA's authority. Either could be as powerful as their creator wills them to be.
So the question falls more to: are the presence and TOAA equal? Their depictions make that really hard to tell.
Some people would say the presence is closer to TLT in power, more of a controller/ caretaker of the DCverse than its absolute supreme power. And the fact that the presence was replaced does support that. Which would mean that TLT is stronger than the spectre.
A lot of people would probably say that The Presence and TOAA are equal, and the comics have supported that at times.
I personally think TOAA is more powerful, he is more portrayed as the embodiment of the author's and audience's will, making him more akin in power to the Overmonitor than to The Presence. So personally I feel TLT is stronger than spectre.
The Living Tribunal is far far stronger than The Spectre because he is the complete Embodiment of the Marvel multiverse, and of all its abstract entities. As such, even the likes of Eternity, Infinity and Death are just a part of his being. Though still portrayed as the Multiversal Judge and greatest of all the Abstracts, the previous Cosmic Hierarchy now holds no meaning in the 8th Marvel Multiverse, and as such he was killed by both Lord Chaos and Master Order. Though he has since been revived, and the hierarchy was restored. Fully Omnipresent.