As far as the show goes, They can travel through time, destroy planets and are considered to some to be a "master species/race", however, with that being said, as to quote the Doctor, "Books are the best weapon". Daleks have no books and find them barbaric and therefore the answer based off of Doctor's answer, would be : " No; Daleks do not have the most powerful weapons"
The most powerful.
Mark I Dalek (The Daleks) Mark II Dalek (The Dalek Invasion Of Earth) Mark III Dalek (1965-1984) Dalek Emperor (Evil Of The Daleks and Parting Of The Ways) Dalek Supreme (Planet Of The Daleks) Necros Dalek (Revalation Of The Daleks) Imperial Dalek, Special Weapons Dalek, Renegade Dalek (Remembrance Of The Daleks) New Series Dalek (2005-TBA. Daleks will return in 2010's "Victory Of The Daleks").
The world is leveled so eventually around level 18+ the most powerful weapons appear on enemies and in stores.
Yes they are. They are one of the World's most powerful weapon has ever made.
More powerful weapons
Nuclear weapons render the most widespread devestation.
The most powerful weapons mentioned in the Mahabharata epic are the Brahmastra, the Pashupatastra, and the Narayanastra. These divine weapons were capable of causing immense destruction and were used by various characters in the epic during the great war.
non-violence and hunger strikes
Daleks can destroy Cybermen through their advanced weaponry and superior technology. The Daleks' energy weapons and ability to regenerate make them formidable adversaries in battle against the Cybermen. Additionally, the Daleks' strategic thinking and aggressive nature give them an advantage in combat.
There tails are one of their most powerful weapon.
The Doctor or the Daleks.
nuclear weapons of the fission fusion type, the so called H-Bomb, are the most powerful of all weapons but their ouput can be tailored for specific purposes. Whatever their size they are inevitably more powerful than any conventional explosive.