Winter!: Prepare for holiday gaming!
Space Quest 1 (enhanced), 4, and 5 are VGA (320x200), Space Quest 2 and 3 are EGA. and Space quest 6 was the last and only game to be released as a SVGA 640x480 resolution game.
If you play them in order, you get the entire storyline, and all the back references to the previous games. That said, the games were produced and released on vastly different budgets and computer hardware. By todays standards, playing the first 5 games would be like playing on a Nintendo DS in terms of graphic quality.
The games are really funny, and like other Sierra Quest series, make use of pop culture and mythologies of the day. (Where Kings Quest used a lot of mythology, Space quest makes references to Science Fiction movies a lot.)
Space Quest 4 and 5 had to be my favorites. SQ4 has you travel forward to Space Quest 12, 10, and backwards in time to Space Quest 1 (to the original EGA version) for probably the best time travel joke in the game. This gets reused in the VGA version of SQ1, in which the time machine appears as you leave.
Space Quest 5, is the only time where Rogers is in command of his own ship (a la startrek), and makes reference back to events in Space Quest 4 and Space Quest 2.
So you really do need to play all of the games to get the most out of it. Even though technology has changed, the games are still fun, and do not require huge time investments to play.
Game Traits applied to Space Quest Collection (PC) by Kisai