Just thinking out loud today.
Why this class rules: The perfect class for the macho hero type. You can use any weapon. Most suits of magic armor will be sized to you. In some games this class puts you on the fast track to knighthood or other cool warrior culture status.
Why this class sucks: With no weapon specialization rules or anything like that there is precious little that you are good at that Elves and Dwarves can't do as well. Some people find the fighter dull as dishwater. Most parties expect fighters to act as meatshields.
Why this class rules: You fight almost as well as the fighter types, but you also get cool powers. Using Turn Undead at the right time to route a pack of ghouls or a vampire will make you the hero of the table. God is literally on your side.
Why this class sucks: No spells until level 2 is pretty damn bogus. I don't even like clerics and I think that's a travesty. Any DM worth their salt will pimp you over at least once with some sort of deadly quest bestowed by a high-ranking member of your hierarchy.
Why this class rules: Fireballing jerkwads will never go out of style. You have a specific problem, use spell research to come up with a custom solution. A lot of kickass magic items are specifically designed for your class and at high enough level you can make your own.
Why this class sucks: Getting over the hump from 1 hit point and 1 spell per day to 5th level fireball lobber ain't easy. Some DMs are dillweeds when it comes to making spells available.
Why this class rules: With only d4 hit points most sane parties won't expect you to constantly check for traps or scout ahead. In BX you can wield damn near any weapon. Some players will expect a small amount of intraparty theft, since this class is literally built around the concept of greed.
Why this class sucks: That d4 hit die really seems puny when you are in a small party and don't have enough muscle to protect you. Most of your skill percentages totally suck. If any kickass magic items go missing you will be the #1 suspect.
Why this class rules: Good hit points and great saves make you tough to kill. Your ability to find traps and listen at doors makes you a useful point man and the fighter can even shoot over you. People tend to expect you to be grumpy or a lush, so you can behave badly and get away with it more often.
Why this class sucks: Most magic armor found will be sized for the fighters and clerics in the party. Some folks will expect you to scout ahead, what with your infravision and trap-finding abilities.
Why this class rules: You have the best of both worlds: kicking as much ass as fighters and throwing spells like magic-users. In fact, throw in infravision and languages and you're better than those guys. Immunity to ghoul paralysis ain't nothing to sneeze at, either; One ghoul is all you need to utterly ruin a 1st level party.
Why this class sucks: The XP chart. It gets really annoying to see all the other players zoom past you in levels. Also, some fairly common monsters (hobgoblins, orcs) seem to just straight up hate on you.
Why this class rules: Great saves. The ability to hide from danger. Many players expect little or no contribution from you, allowing you to shirk many hazardous duties. The fact that this class tops out at 8th level means that if you make it that far you can declare yourself to have 'won' the game.
Why this class sucks: You look like a tasty bite-sized snack to most monsters in the dungeon. Good luck finding magic armor that fits. Trudging through dungeons barefoot strikes me as a bad idea.
I totally understand people wanting more classes in their games, but whenever I start thinking about all the cool things you can do with just these seven it suggests to me that the others aren't necessary. I'd play any of the classes listed above.