I admit, I did not watch Babylon 5 all the way through. I'd tried before to get into it during the earlier seasons, but just couldn't get past the stilted acting and dialog. Jumping in at the beginning of the fourth season proved just right; I got to see several characters' crowning moments: Londo's scheming against the Shadows culminating in a wonderfully snarky speech (with a flashback to Vir's earlier crowning moment, as added payoff), and Bester's calm exposition of what had really been going on for an entire season (to paraphrase Rommel: "Bester, you magnificent bastard.").
Great plots can't fix bad acting, but they can make up for it. Especially if there's some good acting as well: half the characters (Londo, G'Kar, Garibaldi, Bester, and Ivanova, to name as few as possible) sizzled, which made the deficiencies far more tolerable. Despite its corniness, the last episode left me full of bittersweet ache, showing just how much couldn't be fixed despite the best efforts of all involved. I can only hope that Londo's fatal visions concealed a larger story which saw his enemies choked metaphorically as he was literally, at the hands of his Alliance friends.
The metaphors are fairly easy to tease out: though complex and gritty, the setting is often unsubtle (e.g. - "OBEY" signs in the PsiCorps). The one that struck me most is this: the next wars being the Mind Wars seems a worrisome metaphor for the direction of human psycho-social research. Our understanding of the mind, though still somewhat infantile, is growing by leaps and bounds. To pretend that won't be weaponized is to ignore every bit of history since simians decided to leave the trees.