Ok,
even though i'm 17 i've been gambling for a good decade or so now

so will have to base my opinions on the £5JP machines.
Good:
Any JPM in the Rollercoaster/kung fu/caesars palace era. But those machines probably the pick of the bunch Barcrests of this era also deserve a mention too.
Psycho Cash beast - One of the only modern machines where you actually feel some degree of skill in what you're doing, didnt include Fort boyard/big brother as i prefered the fact you could steal a quick JP from zone 4 and to the best of my knowledge you can't do that on the others.
Impulse. Great graphics, and i liked the gameplay too, mentions go out to Spin on it, Wipeout, and fortune and glory, which deserves a mention as i own one

. Shame barcrest now own maygay/impulse now :-(
Crazy fruits/pac man. *ducks* now i know that's really not a wise choice as now any intelligence you credited me with is probably long gone, but for pure playability alone they deserve to be there.
Bad:
Any of the newer barcrests. Who wants to play a machine where it costs £5 to get a board when a JP is £5, probably more playable on £25, i have fond memories of Gimme Gimme Gimme whilst on holiday at center parks, that was always an entertaining game to play.
Championship soccer. Biggest pile of $&%# ever. complete farce of a machine, no playability whatsoever, BWB really made a great job of ruining this.
Modern bellfruit/barcrest machines, and unfortunately as these guys now control almost the whole fruit machine industry, it's not looking good for the AWP industry, i remember a £25 jack the kipper being a total twat, but i remember big cheese not being much better.
Marathon of a first post lol.
Cheers
Drpepper.