Conventional military wisdom seems to favour the 'combined arms' approach, with a mix of capabilities to provide tactical flexibility in fluid role-based battlegroups. Screw conventional wisdom! Those kind of lists are obvious, effective and a bit dull. Instead, let's talk about whatever wacky do-or-die, it's-crazy-but-it-might-just-work lists people can think of.
My focus is on Orks, so that's what I'm going with. Trying to get away from the usual air assault, skorcha horde and gargant mob standards, these were the list ideas that sounded fun to me:
1) Walking with Dinosaurs (Snagga Snagga's Feral Ork Horde)
This list can't really do combined arms well, in my opinion, due to a lack of units to fill support roles. There's very little speed (Junkatrukks don't hit that 30cm sweet spot, and Boarboys are only fast on the charge) and a maximum weapon range of 60cm.
However, I do like the look of the Orkeosauruses. War engine transports with 4+ Reinforced Armour, 6DC and a critical effect that isn't "This unit and everyone on board is destroyed" like every other Ork option? That sounds groovy. They even pack some long-range (for this list) guns and some pretty decent CC attacks.
The cheapest way to get them is in Wildboyz formations - 300 points minimum, but I'd probably splash on a Wyrdboy and two units of Boyz + Grotz. The Wyrdboy can be added to any unit in the formation, and I assume this includes the Orkeosaurus - that's an extra MW shooting attack out to 45cm, and a 5+ AA MW which takes six BMs to suppress. For 400 points, the basic unit looks like:
Orkeosaurus w/ Wyrdboy
It seems like it would take some effort to slow that unit down, it can throw some BMs around, and it's very assault-resistant. Sadly it's slow as heck, and will likely never get near the enemy Blitz, but could easily guard home objectives or plod across to the enemy forward objectives while shedding BMs like crazy.
This is the list I'm tempted by:
Wildboyz (Big) - 700 points
2 Orkeosauruses w/ Wyrdboyz
4x Wildboyz - 400 points each (1600 total)
Orkeosaurus w/ Wyrdboy
2x Junka Brigades - 275 points each (550 total)
7 Junkatrukks (1 w/ Wyrdboy)
Trappas - 150 points
6 Wildboyz w/ Scout
One dinosaur on each home objective, three stomping across to the enemy objectives, Trappas to provide a forward nuisance/roadblock (or Teleport/Air Assault protection, though the Orkeosaurus units don't really need it) and Junkas to provide a distraction or late-game Blitz rush depending on whether the enemy puts any fire into them.
2) Deep Impact (Orkstein's Gargant Bigmob)
This one is purely a gimmick, but I'd love to see the look on an opponent's face the first time you pulled it off.
The central element is a Great Gargant with the Transporta upgrade, filled up with angry Orks, planetfalling onto the enemy objectives at the start of turn 3. There's really not much more to it than that - it should annihilate practically any opposition when it assaults, and it will be very difficult for the opponent to destroy it to Break the Spirit before the game ends.
There are many problems, not least of which is that half your army will be off the board until turn 3. If your opponent also brings a spacecraft, and you lose the roll-off to determine the turn your Battlekroozer arrives, you pretty much lose the game.
The core of the list:
Battlekroozer - 200 points
Great Gargant w/ Transporta - 900 points
2x Loota Warbands - 275 points each (550 total)
6 Killa Kanz
You can obviously play around with the Loota warbands a bit, but I think the Killa Kanz provide maximum punch point-for-point. You could get serious punch by switching one out for a unit of Big Gunz with an Oddboy, taking the Mega-Choppa upgrade - that gives you a 3+ CC unit with EA(+1), TK(D3) weapons for 50 points - or trade hitting power for resilience by swapping four of them out for two Dreadnoughts. I like having the two formations for the potential to take on multiple enemy objective-holders, but obviously you could also go for a single blob of troops.
The problem also becomes what to do with the rest of the list... you'll need to hold your own home objectives and soften up the enemy a bit, while hopefully being resilient enough to stay on the board under two turns of beating from the entire enemy army.
I'd be tempted to take another Great Gargant and make it your Warlord (otherwise the drop Gargant has to be your Warlord, and you can't use its reroll for two turns). Unfortunately, giving it a Big Upgrade (like a Wyrdboy tower) would push it up to equal top points for BTS, so you'd have to skip that. (Normally you'd add a Killa Kan or something to the other formation, but an Ork War Engine in a formation with non-War Engine units can only transport units from its own formation.) This also gives you a laughably low number of activations. However, all the remainder of the army has to do is to try to make the opponent keep away from your objectives for a while, and not many things want to tangle with a Great Gargant up close. Add in some garrisoned Loota warbands and maybe a unit of Fighta-Bommers to provide some much-needed air cover or soften up key targets, and you're good to go.
I really doubt this list would be effective - not even counting the games where an opponent's spacecraft cock-blocks you and you auto-lose - but even though there are plenty of ways to counter it, it could be quite fun when it works. The main difficulty with Gargants (in my experience) has been keeping them alive long enough to trundle across the board and get stuck in - this totally bypasses that process and drops one unscathed in the enemy's face. Good times.
So, what other crazy lists are out there? Anyone got any cool and barely-workable ideas?