Here is a version of a dedication of merit's prayer that I like.
By this virtue may I soon
reach a Guru-Buddha-state,
and lead each and every being
to that state of Buddhahood.
May the precious Bodhicitta
not yet born, arise and grow
may that born have no decline
but increase forever more.
In all my rebirths may I never be separated from perfect spiritual masters
and enjoy the magnificent Dharma.
Completing all qualities of the stages and paths,
May I quickly achieve the state of Vajradhara.
May anyone who merely sees or hears,
remembers, touches or talks to me,
be instantly freed from all sufferings
and abide in happiness forever.
It is only from the kindness of my Guru
that I have met the peerless teachings of the Buddha.
Thus, I dedicate all merit so that all sentient beings in the future
may be guided by kind and holy Gurus.
Until cyclic existence ends,
may the beneficial teachings not be blown away by the wind of superstitions.
May the entire world be filled
with people who have undersdtood and found firm faith in the true teachings.
Day and night, may I pass the time
thinking and examining by what means
these teachings can spread
in the minds of myself and others.
May all sentient beings - who have all been my mother and father - be completely happy,
and may the lower realms be forever empty.
May all the prayers of the bodhisattvas, wherever they live,
be immediately fulfilled.
May the glorious gurus live long,
and may all beings throughout limitless space have happiness.
By purifying our defilements and accumulating positive potential,
may I and all others be inspired to attain Buddhahood quickly.
May I never develop, even a moment,
wrong views towards the deeds of my glorious Gurus.
With respect and devotion, by seeing whatever actions they do as pure,
may the guru's inspiration flow into my mind.
In whatever way you appear, O glorious Guru,
whatever your retinue, lifespan and pure-land,
whatever your name, most noble and holy,
may I and all others attain only these.
In order to follow the excellent examples
set by the wisdom of the bodhisattva Manjushri
and the always sublime Samantabhadra,
I dedicate all virtues to their peerless ideals.
All conquerors of the three times
have praised this peerless dedication as sublime.
Therefore, I also surrender all roots of my activities
to the sublime goals of a bodhisattva.