Personal opinion...
Halo-Good story.Gameplay pretty nice.Community sucks(the ones that talk at least).Horrible balance on the weapons,I'll never forgive bungee for what they did to the shotgun in halo 3.
Halo 2 is the best of the series in my opinion.
The hype is excessive.
Half-life-Wonderful story.Good modibility(something halo will never have).Gameplay pretty nice.Community... mixed bag,a good deal of nice people,but some jackasses and hackers roam the lot.Weapons are pretty good.Great method of playing out cinematic scenes without taking control from the player.
Overall I feel the hype is well earned.
Idiom,you are looking for straight shooter mechanics,this game is not memorable for that,the story it self is and and puzzles,don't forget those.You don't like suspenseful plots and I understand that.However I think LOST is far worse about that than this game.
LBP-I'll never play this,there is no way I'm going to afford a ps3 anytime soon,and even then LBP is low on my list of games to purchase.
Gears-Not exactly crazy about the story.Modibility,I'm not sure what that is like for the PC,but I know there's no point for the xbox.Gameplay,clunky,but the guns are satisfying.Community,rather smaller than I anticipated,some similarities to halo,but on a lesser magnitude.Weapons,satisfying,I already said that,yay,moving on.Blarg scenes.
Hype,overrated.Ok I guess,but there are many games I'd rather enjoy.