The AMC drama begins filming its final eight episodes next month, and Cranston briefly discussed the series at last night's BFI London Film Festival screening of Argo.
"It's the role of my life. Walter White in Breaking Bad, I'll never have a better role than that," Cranston said.
"I'm grateful for it, and I embrace it. When it's time to walk away I'll be sad, but it's a great experience."
The role of White has won Cranston three Emmy Awards for 'Best Actor in a Drama'; he lost out for the first time this year to Homeland star Damian Lewis.
The fifth series of Breaking Bad will be available on Netflix in the UK from November 1.
Cranston's co-star Aaron Paul recently told Digital Spy that his view of his own character Jesse Pinkman evolved throughout the show's first season.
"I initially viewed him, as did everybody else I think, as just a burnout druggie," Paul said.
"But then even as season one went on, and especially when season two started, he had so much more going on beneath the surface. You really saw that he was a good kid, he had a good heart, but he was definitely lost and struggling to find his way."
> 'Argo' LFF premiere: Ben Affleck, Bryan Cranston talk CIA thriller - video
The first half of Breaking Bad's fifth season will be available on Netflix in the UK from November 1.
Watch a promo for the season below: