I'll fight to keep these in the house....
Infinity the Game. Great decision making that glosses over the annoying amount of special rules. Amazing art and production values. Good mechanics, crying out for a simpler WW2/modern conversion and a decent campaign system. A great game that rises above its flaws.
LoTR:SBG+Battle Companies/Legends of High Seas/Old West/Gladiator. A surprisingly subtle and underrated game engine. Clean design that gave birth to a range of skirmish campaign systems. Easy to learn, and easily adapted with house rules - samurai and medieval mods are also available.
Force on Force/Tomorrow's War. Looks simpler and quicker to play than it is. Can "bog down" with all the reactions, counter-reactions. Lots of rules explaining specific situations. Still the most interesting modern combat/near future sci fi games, for me, with lots of hard decision making.
General Quarters I/II/III. The first two books have a sensible amount of record keeping for a naval game. I'm currently fiddling with an aeronef adaption.
Battlestations! Battlestations! For fleet level naval actions. Good design philosophy, clean execution.
Bag the Hun/Check Your Six. Two very different aerial rules, for very different reasons. BtH has a great activation system, but inconsistent game mechanics. CY6 has good mechanics but annoying written orders.
A Fistful of Tows 3. A lot of good design ideas in this modern armoured warfare game. Would love to see a proper sci fi adaption with a simpler-to-use unit builder.
Song of Blades/Song of Our Ancestors. SoBH is like a box of LEGOs. You spend more time making warbands than actually playing the game. SooA is a spin-off book for the wonderful world of the Quar. A whimsical, wonderful, coffee-table rulebook.
Chain of Command. The pre-game scouting phase is awesome. The emphasis on "Big Men" and spotting gives a real flavour to WW2 gaming. I also like Sharpe Practice - pity I never play Napoleonics...
Secrets of the Third Reich. A weird war game that is very simple, yet still more realistic than Bolt Action. Great vehicle building rules for using DUST and MaK mecha as well as random 1:48 models.
Savage Worlds. The ultimate toolkit for cinematic RPG skirmish, plugs into some really cool settings (weird war/pulp/fantasy.)
DBA. A triumph of simplicity and elegance. The only mass battle ruleset I have minis based for.
Battlefleet Gothic. I couldn't afford the models so I played with cut-outs made of ice-cream lids. Stood out from the usual Full Thrust clones. Even had a campaign system.
Musket and Tomahawk. SAGA's lesser known sibling. Interesting blend of familiar and new ideas for French and Indian Wars.
Hind Commander. This helo game is unique, with both interesting game mechanics and its niche focus. I'd like to see more from this author.
Shipwreck! For proving not all modern naval games are gluggy and unpleasant book-keeping marathons.
Cutlass! A fantasy pirates skirmish game, with interesting activation and a deep campaign system.
Heavy Gear. Another great concept DP9 managed to stuff up. Combined arms mech warfare pitched at the right level. Not a bad ruleset, but core rules and errata confusingly scattered through several volumes, married to an overpriced miniatures line. So much potential.
Lightning Strike. I LOVE these rules. Perfectly captures anime Gundam battles in space. A much tidier game than Heavy Gear. Pity that DP9 never bothered to make a proper line of miniatures for them.
HAVOC. Another set of rules I like but never play. Great ideas, but terrible rules layout and lack of an army builder means it plays second fiddle to SoBH, despite it's superior gameplay. I look at this wistfully and think "if only."
Battlefield Evo/Starship Troopers. A fascinating look at the way 40K could (and probably should) have progressed. The WW2 spin-off Victory Decision seems to have a small but devoted following.
Malifaux. Overly complicated rules - plays like a bad CCG. Excellent scenario generator rescues it from the shed.
Wings AT War. No, not the one you're thinking of. Aerial rules put out by Tumbling Dice. An interesting series that focuses on energy management, but is very bare bones otherwise.
Fairy Meat. A game of 1:1 scale fairy combat between cannibalistic woodland sprites. Just because I enjoy the fact a wargame like this exists. Quite a good game, to boot.
ADDED: Dropzone Commander. This has an excellent air-armour-infantry synergy - you need infantry to capture and hold objectives, but vehicles to get them there/interdict opponents. Thought has gone into scenarios and use of terrain.
These go straight into the box in the shed...
Spinespur. An overly complex skirmish game, with fluff including rape. Unpleasant AND bad.
Warhammer 40K. 5th edition? I've lost interest in the codex "arms race" a long time ago and GW's business practice slashed and burnt my remaining goodwill.
Warzone/Vor/Wargods of Aegyptus. R.I.P. They all died a long time ago.
Flames of War. Not interested in replicating all the faults of 40K in 15mm WW2.
Iron Ivan rules. (Coffin for 7 Brothers, Thrilling Tales, etc) Not bad, just kinda bland. Other rules do the same eras, only better.
Fields of Glory/DBM/Impetus. Yawn. Zzzzzz.
GASLIGHT. VSF toolbox that's OK, but very overrated by its fanboys.
AE:WW2/AE:Bounty. WWW2 and pulp sci fi skirmish rules that never took off. Restrictive warband choices and some weird design ideas.
Helldorado/Anima Tactics. Beautiful books, great production values, cool background/fluff - but overly complicated gameplay.
Future War Commander. I found the rules surprisingly inaccessible and how the anti tank/anti infantry dice worked didn't make sense.
Rapid Fire. WW2 platoon level combat is a crowded market. It's probably my 6th choice rules for this genre.
5150. An early 2HW offering with typical (for the time) obscure layout and editing.
5150: Star Navy. A space game so abstract you might as well remove minis altogether and randomly roll dice against each other.
Battletech. Anything with that much recording really should be a PC game. Wait, it is....
Star Fleet Battles. Fun for accountants, maybe?
Dungeons & Dragons 4th Ed. If people actually use this for any sort of miniatures gaming... ...ugh. just ugh. It's not even a good RPG.
War Rocket. The asymmetrical movement was vaguely interesting, but everything else wasn't.
Babylon 5: A Call to Arms. An exercise in meaningless dice chugging.
ADDED: Firestorm Armada. It takes a particular skill to borrow so heavily from other games (Battlefleet Gothic in particular) and yet make a worse game. You're meant to pick the good ideas! If you want to push spaceships into the middle of the table and chug handfuls of dice until someone wins, fine. The bad news is they used the same engine on all their other games.
Disclaimer: There are about 80 other books which simply went into the "neutral cupboard" and I'm excluding about 150 more pdfs. Also, the big clean up is not finished - I'll edit and add to this list as more come to light.