There are good episodes there and frankly I think everyone is wrong about that. Sure there are episodes that can put you off, some very slow boring ones and it generally looks worse and is a bit more hammy. But that is part of any series, you need to watch from the start to grow into the characters. I think if you like the Star Trek... theme/lore/whatever then you would persevere through either series 1, or 3.
TNG isn't my favourite tv, if I rewatched it there are plenty of episodes i would skip. DS9 is so much better as a show because of the season story arcs and the entire series arcs that make even the more boring filler episodes part of something greater. Thats what started early in the 90's, Babylon 5, X-files, DS9, entire shows with seasonal and series based arc's, it makes everything so much more fleshed out and meaningful.
That's why you can really get away with starting TNG just about anywhere, mostly it's just single episodes, outside of getting to know the characters you won't not understand any part of the show if you start in the first or the last series. DS9 you have to watch from the start, Babylon 5 is still worth watching as well.