Sliders as it started out was a drama comedy with a lot of fresh and intelligent ideas, the character's were well drawn out and the fact that you had a group of travellers who were all very independent of one another was different, they constantly separated and went their own ways and did their own thing (in particular see 'The Weaker Sex' which is one of my favourites). The constant use of TV shows as orientation for each new parallel world was also a strong element that you wouldn't see anywhere else as far as I know. Unfortunately the comedy aspect which in Season 1 made a good show great was in season 2 reduced heavily. Other elements introduced in season 2 I didn't like was the constant mention of the Dominion hotel. They had a recurring hotel in the first season but it wasn't mentioned so forcefully. The show in Season 2 still had the ideas but like I said the comedy was lost and it became straight science-fiction drama, a shame in my opinion. Season 3 at first followed in-line with season 2 with some great ideas and good drama (especially 'The Guardian'). However another downfall of Sliders became far more prominent from the first episode of this season, and that is the use of guns to sort out problems (just watch the title sequence for each iteration of the show and you'll realise how much guns are prominent in the later Seasons). Until then the use of guns was something that hardly ever appeared and never as a problem solver. This plus Rembrandt Brown's ongoing change in character into more serious and macho, led to the final part of the season where Guns became the be all and end all of everything (that and movie rip-offs due to lack of ideas, I cringe at 'Dream Master's' a take on Nightmare on Elm Street and the first really bad seed). They obviously wanted a military aspect introduced and it didn't suit the show in my opinion. They didn't follow things up from earlier in the Season either as a obvious recurring bad guy would have been Quinn's female double Logan St Clair. Instead she doesn't show up ever again and we get Colonel Rickman (my guess is it was supposed to be Logan St Clair originally but because they were introducing Maggie they wanted to ground her character with someone she knew). They also decide to kill off Quinn's mentor (most eccentric and best character) Professor Arturo and replace him with the Angry Military Woman (Maggie Beckett). The thing is that we'd found out earlier in season 3 that he was dying anyway so the way they killed him off made no sense and sort of undermined his character arc. Season 4 was in my opinion the worst, along with the introduction of the Chandler Hotel (even more of an annoyance than the Dominion from season 2 because at least the Dominion was a different hotel each time) the re-introduction of the sliding bad guys The Kromaggs (from a season 2 episode which was good but personally I wanted to see a whole episode set in Frenchland) as Nazi's was badly thought out and they didn't know what to do with them despite being in 7 episodes or something it felt more like 15. Ideas became thin as well with almost a pointless plot thread where Quinn was from a parallel Earth pretty much wasted. Really it was only to introduce a brother character for Quinn and nothing much else. Talking about Colin I quite liked him actually, I think the actor's (Jerry O'Connell's brother) performance was judged unfairly as he was supposed to be flat in the way he talked. One thing that in this Season didn't work for me was Wade being captured by the Kromaggs and Maggie almost acting like a less interesting replacement. It made sense to get rid of Angry Maggie but she wasn't her own character basically. Thankfully, the final season improved upon this as she became more motherly.
With Season 5 we lost our main character Quinn and his brother Colin. This was a major sea change as Rembrandt was now the only Original character left and was morphed into almost an old man. This kind of worked but dragged, when the idea of him being tired of Sliding comes up you can kinda see it. 2 new characters are introduced in this season with Diane a scientist (the science aspect had somewhat fell by the wayside in the last 2 seasons) and Mallory the cheerful Jock. Although they weren't great characters it sort of felt nice to have the elders and the youngsters dynamic at times. The main problem with this Season was that although it had some good ideas (definitely better than Season 4) it had no budget what so ever. This resulted in a flatness as such mainly because everywhere looked the same, everywhere looked like a grey corridor. It at times looked like it was filmed by an amateur as well. You can clearly see them trying to address a balance that had been lost in Season 4 but it only half working. The Kromaggs and the name dropping of the Chandler hotel were greatly reduced and I actually found the military episode (Strangers and Comrades) to be extremely enjoyable. This is particularly ironic considering my opinion that Guns are partly to blame for the series Ruin. So definitely worth it in particular for the first Season but also the second. It's worth watching Season 3 as well just to see how the show changes the way it does.