Suu Kyi and her party are expected to make sweeping gains at the polls slated for October or November in what is seen as one of the greatest tests yet of the former military-ruled nation's transition towards democracy.
The Nobel laureate, who entered parliament in 2012 after landmark by-polls following a decades-long democracy struggle, said this year was a "very important time" for Myanmar, which was ruled by the army for nearly half a century.
Suu Kyi, who is currently barred from becoming president by a junta-era constitution, also called for "clean politics", free from trickery and coercion.
"Only if we have clean politics can our country develop in peace," she added.
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The opposition leader has declined to completely rule out a boycott of this year's poll as she campaigns to change the constitution.
Analysts say she is unlikely to succeed in changing the charter in time, as she faces strong opposition from military MPs who hold a quarter of parliamentary seats.
But her supporters say her central role in the country's political future is not in doubt.
"She has been very important for the last 20 years and will remain just as important in future years for our party and our country," said Nay Soe Aung, an information officer for the youth wing of her National League for Democracy (NLD).
Further celebrations are expected over the weekend by her party, which is holding its annual senior level conference on Saturday and Sunday in Yangon.
Myanmar began emerging from military rule in 2011 following an election marred by widespread accusations of cheating and the absence of the NLD.
Suu Kyi was freed from years of house arrest days after the 2010 polls and has since led her party into parliament.