There are no overlevel penalties for epic quests. Meaning a level 27 still gets full xp from running a level 20 quest on EN. With that in mind, here's a (partial) list of high xp/minute epic quests, factoring in the time it takes to run to them given the ability to teleport, greater teleport, and key to eveningstar:
Very Good (>5k/minute)
Spies in the House
VON3
WizKing
Impossible Demands
Rusted Blades
Good (>4k/minute)
An Offering of Blood
Fathom the Depths
Death Undone (may need to drag along the level 23 or 24 rogue hire to hit the 80 open lock)
Trial By Fury
Trial By Fire
Tor
Outbreak
Druid's Curse
Acceptable (>3k/minute)
Thorn and Paw
Overgrowth
Claw of Vulkoor
Big Top
Unquiet Graves
Lords of Dust
Deal and the Demon
Closing the Rift
Don't Drink the Water
I believe Through a Mirror Darkly ends up in the "good" category, but I haven't been including it in my xp farming. (Which is thankfully done for the time being.) Some quests feel like they might be good, but after running a few time trials I found them to be <3k/minute and so discarded them. (Most were in the 2500-2800/minute range.)
Poor
Bargain of Blood (long run out to it, very low xp)
Snitch (it's fun enough to include in a circuit, but it actually takes longer than it feels)
Over the past weekend, with the epic xp bonus days, I buckled down and farmed out 4 million xp to finish off my main's last martial past life. It ended up being five circuits, all between 40-55 minutes long, to maximize my old-style ship buffs. (Namely the 5% xp shrine.) Other than the ones listed above, the Gianthold and High Road quests were barely good enough to include.
Code:
Circuit 1
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- Trial By Fire (second teleporter option from NPC)
- GT back to Gianthold
- Cry for Help (first teleporter option from NPC)
- GT back to Gianthold
- Cabal for One (super low xp/minute; switching to Feast or Famine might be better)
- GT back to Gianthold
- Tor
Circuit 2
---------
- Key to Eveningstar, acquire all quests in this circuit before starting if needed
- Rest Stop
- A Stay at the Inn
- Lost in the Swamp
- Impossible Demands
- Unquiet Graves
- Acquire MotU quests for circuit 4 (rusted/death/trial/deal/reclaiming)
Circuit 3
---------
- VON3
- Key to Eveningstar, sell/repair at bar
- Acquire Oubreak & Overgrowth if needed
- Outbreak
- Overgrowth
- Sell/repair
- Thorn and Paw
- Druid's Curse
- Collect 3 cleric comms (unbound DW pots)
- Re-acquire chain, outbreak and overgrowth
Circuit 4
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- Lords of Dust
- Rusted Blades
- Recall once
- Death Undone
- Recall twice, enter demonweb
- Trial By Fury
- Deal and the Demon
- Reclaiming the Rift
- Key to Eveningstar
- Don't Drink the Water
- Collect rewards and re-acquire all quests in this circuit
Circuit 5
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- Offering of Blood
- GT back to zawabi, re-acquire, teleport to House P
- Big Top
- Gate 1: Straight (Blue = Yellow X)
- Gate 2: Left (Green = White Triangle) Right (Yellow = Red Diamond)
- Gate 3: Right (Orange = Green Circle) Left (Purple = Yellow Square)
- Re-acquire, house teleporter to Kundarak, sell/repair in Fens
- Fathom the Depths
- Claw of Vulkoor
- Teleport to Deneith
- Spies in the House
With my 5% cannith pots, master's gift, 5% ship buff and bonus weekend, this generated a little over a million xp a day.
If I ran EE and wasn't soloing, I would probably focus on True Elite sagas instead of blasting through for fast completions.
EDIT: Running 26 different quests each day definitely solves the "too repetitive" problem of xp farming, but fair warning that blasting through all five circuits each day gets very grindy very fast. After four days I was super stoked to be finished.