The spelling of /b/ is either <b> or <bb>, and /t/ is either <t>, <tt> or <th> in Thai. I have included singulars and plurals of words which have the contrast finally, even though these may not be strictly minimal. I have discarded the pairs found by the computer in which the contrast was made twice or in different places in the word such as babble/tattle or bat/tab. Notice that the homograph tear turns up making several different contrasts.
The contrast is between a voiced and a voiceless plosive fairly well apart in the mouth. There might be a small problem when the contrast is word-final using an unreleased allophone, but I have not heard of it being a problem even for Dutch and German speakers who tend not to voice final stops.
There are two pairs involving a slight danger of embarrassment: bird/turd and boob/boot.
Interesting pairs include
aback attack Abe eight adverb advert B T B's T's baa ta baa tar baa'd tarred baas tars babble battle babbled battled babbles battles babbling battling babe bait babel table babels tables babied baited Babs tabs baccy tacky back tack backed tacked backing tacking backs tacks bacon taken bag tag bagged tagged bagging tagging bags tags bail tail bailed tailed bailing tailing bails tails bail tale bails tales bake take bakes takes baking taking baker taker bakers takers bale tail bales tails baling tailing baled tailed bale tale bales tales balk talk balked talked balking talking balks talks ball tall bally tally ban tan banned tanned banning tanning bans tans bangle tangle bangles tangles bank tank banked tanked banking tanking banks tanks banker tanker bankers tankers banner tanner banners tanners bar ta bar tar barring tarring bars tars barber barter barbers barters bare tare bares tares bare tear baring tearing bares tears barn tarn barns tarns Barry tarry Bart barb barter tartar barters tartars based taste bask task basked tasked basking tasking basks tasks baste taste basted tasted bastes tastes basting tasting bat tat bats tats batted tatted batting tatting batter tatter batters tatters battle tattle battled tattled battles tattles battling tattling batty tatty beak teak beam team beamed teamed beaming teaming beams teams bear tare bears tares bear tear bears tears bearing tearing born torn borne torn beau toe beaux toes beck tech becks techs bed Ted beds Teds beer tear beers tears be tea be tee being teeing bead teed bee tea bees teas bee tee bees tees Beith teeth belle tel belles tels belle tell belles tells bell tel bells tels bell tell belling telling belly telly bellies tellies ben ten bens tens bend tend bended tended bending tending bends tends bent tent Bern tern Bern turn Bernie tourney berry Terry Bess Tess best test bested tested besting testing bests tests bhang tang bhangs tangs bib bit bicker ticker bickers tickers bide tide bided tided bides tides biding tiding bide tied bier tear biers tears biff tiff biffs tiffs bight tight bights tights bike tike bikes tikes bile tile bill till billing tilling billed tilled bills tills bin tin bins tins binning tinning binned tinned bind tined bine Tyne bine tine bines tines binge tinge binges tinges bird turd birds turds biro tiro biros tiros bite tight bites tights blob blot blobs blots blurb blurt blurbs blurts boar tor boars tors boar tore boars tawse boast toast boasted toasted boasting toasting boasts toasts boaster toaster boasters toasters boat tote boated toted boating toting boats totes bode toad bodes toads boded toadied body toddy bodies toddies bog tog bogged togged bogging togging bogs togs boggle toggle boggles toggles boil toil boiled toiled boiling toiling boils toils boiler toiler boilers toilers bold told bole toll boles tolls bomb Tom bone tone boned toned bones tones boning toning bony Tony boo to boo too boo two boos twos boob boot boobing booting booby booty book took boom tomb booms tombs boor tour boors tours boot toot booted tooted booting tooting Bootle tootle bore tor bores tors bore tore bores tawse bortsch torch boss toss bossed tossed bossing tossing bosses tosses bought taught bourbon turban bourbons turbans Bourne torn bout tout bouts touts bowel towel bowels towels bower tower bowers towers bowing toeing bowl toll bowling tolling bowls tolls boy toy boys toys brace trace braced traced braces traces bracing tracing bract tracked bracts tracts brad trad brae tray braes trays braid trade braided traded braiding trading braids trades braille trail brain train brained trained braining training brains trains brash trash brawl trawl brawled trawled brawling trawling brawls trawls brawler trawler brawlers trawlers bread tread breed treed breeze trees brew true brewer truer brews trews briar trier briars triers bribe tribe bribes tribes bribe bright brick trick bricked tricked bricking tricking bricks tricks bride tried bright trite brightly tritely brightness triteness brill trill brim trim brimmed trimmed brimming trimming brims trims bring Tring brolly trolley brollies trolleys Bruce truce buck tuck bucked tucked bucking tucking bucks tucks buff tough buffed tuft buffer tougher buffs toughs bug tug bugged tugged bugging tugging bugs tugs build tilled builder tilde builders tildes built tilt bung tongue bunged tongued bungs tngues bunnies tunnies bunny tunny buoy toy buoyed toyed buoying toying buoys toys burke Turk burkes Turks burn tern burns terns burn turn burned turned burning turning burns turns burner turner burners turners burn-up turn-up burn-ups turn-ups burps turps bursar terser bury Terry bustle tussle bustled tussled bustles tussles bustling tussling busy tizzy but tut butted tutted butting tutting buy Thai buys Thais buy tie buying tying buys ties buyer tire buyers tires by Thai by tie cab cat cabs cats cabby catty caber cater cabers caters cob cot cobber cottar cobbers cottars considerably considerately cub cut cubs cuts cubbing cutting cube cute cubicle cuticle cubicles cuticles cubist cutest curb curt dauber daughter daubers daughters deb debt debs debts derby dirty derbies dirties diabetics dietetics drab drat dubious duteous ebb ate fab fat fable fatal feeble fetal fib fit fibs fits fibbing fitting fibber fitter fibbers fitters fibre fighter fibres fighters gab GATT gibber jitter gibbers jitters glibber glitter globe gloat globes gloats gob got grebe greet herb hurt herbs hurts herbal hurtle hob hot hub hut hubs huts job jot jobbing jotting jobs jots jobber jotter jobbers jotters knob not knob knot knobs knots Lab lat labour later liberal literal liberals literals lob lot nab Nat NB NT nib nit nibs nits nub nut orb aught pebble petal pebbles petals pub put rabble rattle rabbles rattles rabid ratted ragbag ragtag ragbags ragtags rib writ rob rot robs rots robbing rotting robber rotter robbers rotters robe rote robe wrote rouble rootle roubles rootles rub rut rubbing rutting rubs ruts scab scat scabbard scattered scabby scatty scabbier scattier scabbiest scattiest slab slat slabs slats slob slot slobs slots snob snot sob sot squab squat squabs squats swab swat swabbing swatting swabs swats tab tat tabard tattered tabby tatty taboo tattoo tabooed tattooed tabooing tattooing taboos tattoos tribe trite tub tut tuba tutor tubas tutors tuber tutor tubers tutors web wet webbing wetting webs wets wobble wattle wobbles wattles yob yacht yobs yachtsJohn Higgins, Shaftesbury, January 2010.