Magmavision2000

IMO, TOS and TNG are pretty worthwhile.  I'm still getting through all of TOS...There's also some fun to be had in each of the other series,  but I'm no expert.

I second that recommendation, TOS and TNG are well worth looking into.  In numerous places, you'll find "Top 10" lists for both series, so if you don't want to commit to watching every single episode, use these lists as a guide.  You should see the first six Trek movies as well, but in my opinion you'll appreciate them better if you watch them only *after* finishing TOS.

TNG took longer to "gel" as a series, so the first two seasons get a bad rap, but there are gems to be found there as well.  I'll recommend nine episodes from both seasons to help you steer clear of the dross.  From S1, check out the two-part pilot "Encounter at Farpoint", then "Where No One Has Gone Before," "The Big Goodbye," "Datalore," "11001001," "Home Soil," "Heart of Glory," "Skin of Evil," and "The Neutral Zone."  From S2, check out "The Child," "Elementary, Dear Data," "Samaritan Snare," "The Measure of a Man," "Contagion," "Time Squared," "Pen Pals," "Q Who," and "Peak Performance."  S3 on is pretty solid, with a few exceptions, though the four TNG movies were IMHO a disappointment.

Admitting it is the first step.