i enjoyed seasons 1-4, i've only seen a little bit of season 5, but yeah 5 and 6 seems like they suck.
jd's thoughts some times suck. when they are integrated with what's actually going on in the episode i almost don't like the episode itself. towards the end, cox's speeches started to become boring. how many times can one man yell at another man while retaining the fun factor right.
dr. jan itor and dr. cox are probably the funniest characters though. lot of guest characters that i liked though.