Should I say you're the best? The answer is no. There's nothing that makes people more skeptical than hype.

Compare these statements, and pick the claim you believe more:

"Fastest pizza delivery in town" vs "We deliver your pizza in 10 minutes".
"We have the best italian restaurant" vs "Our restaurant has won 6 Golden Spoon awards in the Italian Food category"
"Cheapest web hosting plans" vs "Our monthly plans start from $1.99".
"Best tasting coffee, guaranteed" vs "Major competitions have voted Esmeralda the consistent winner five years in a row"

I bet you found the second option more believable in each case. People don't believe superlatives, they believe specifics. I understand the urge to want to use superlatives, but always translate them into specifics.