Dialogue

He said, she said, he said... it gets boring after a while. But what do you substitute? He snapped, she interjected, he opined, they averred? Fortunately there are alternatives that are neither dull or cheesy (combine with adverb for maximum effect). I mean to say...

blether chant chunter cluck crow drone enthuse flute gibber gripe gush hector huff intone lecture peep prate prattle snap sniff speechify spit spout squawk tweet twitter utter wail warble whimper whine whinge woofle yap

bitch (“Nice video, shame about the song,” they bitched.)
bleat (bleating about plastic bags Time April 3, 2008)
blether "Ideally I'd love to be like Liz Hurley and do the highbrow campaigns," Jordan blethered. "But the truth is, they never come to me." thefreelibrary.com
bray (what the upper classes do)
cheep ("Hi," she cheeped even more cheerfully than usual. "How are you two?")
chirp (She chirped excitedly. "I'm Alice, nice to meet you!)
chirrup (She chirruped away to Harpers that she has ‘acquired a domestic life'.)
enthuse (He enthused: "I absolutely love the show. John Barrowman on Glee)
flannel ("My resume was very much filled in at the last minute" he flannelled. "I'm just a likeable person who can get on with anyone at any level.")
flute (‘For a philosopher, failure is much more important than success,’ he fluted. Will Self in the LRB 25 Feb 2010)
froth (she frothed)
gibber (When the critical moment came he funked it and instead of proposing marriage he gibbered about newts until Madeline went back indoors. thevervoid.com recounts a Jeeves and Wooster plot)
gripe ("All she could think about was herself and her pride and her ego," he griped. thisisbrandx.com)
gush (“I love your designs, they're so unique,” she gushed about the luxurious goodies. celebritybabyscoop.com)
harrumph (Such a position, he harrumphed, was "simply not sustainable.")
huff ("No, I most certainly will not give you my name," she huffed. ezinearticles.com)
intone ('People wore suits all the time, it was the norm; there was none of this jeans business' he intoned. londonist.com)
jabber (Sathnam Sanghera on what dates do)
keen (equal opportunity keening - Time)
make the right noises (about working on the marriage)
maunder (Wordsworth maundering on about daffodils)
mither (if you’re Alan Bennett)
mouth (Unsupervised, they can act in their own self-interest, while mouthing pieties of the greater good they claim to serve)
pomp while Patrick Stewart “pomped away about art” Andrew Billen T June 14 10
spout (He was then reported as spouting the usual green gibberish about pollution and the Earth's dwindling resources. www.brookesnews.com)
trill (When she first unveiled her new hairstyle, she trilled: "I was complimented by eight MPs and two ministers... Daily Mail 07)