Lots of recommendations here against variety in game play. Strange imo as I find game play variety very important and tend to think most others do as well, especially in a small collection. I don't want two similar machines in a two machine collection. So in using the OP's game list, that means no TWD and MET combination. They are fairly similar, which is not surprising considering they have the same designer, a similar style of PF layout and the same programmer. TWD is the spiritual successor to MET with even better code and a more unique PF layout (Borg has been quoted saying he preferred TWD). But MET still a great game, and theme matters a lot to most people (me included). So pick whichever you prefer. Both are great pins and to get some good variety you can't have both. I agree that both TWD and MET are the two best pins in this list, but I need variety even more than having the two best pins.
So for the second pin what the OP has left is GOT, AS and SW. AS uses the same PF designer (Borg) as earlier so I'd discount it as well to get something more different. That leaves the Ritchie games of GOT and SW. Both are very different playing from TWD and MET as they have much more flow in the playing style. GOT and SW are both quite different from each other as well so I'd pick whatever you prefer between the two. Both pins have their fans and offer some cool fun and differences. SW has less going on with the playfield but it has the LCD, theme and many love its LCD integration. GOT has more toys on the PF and more interactions on the PF. Different people will have different preferences and both pins have their merits.
Frankly, if one of the pins is going to be TWD or MET and I go away from the OP's list for the second pin, a different and great option for variety can include all the JJP and CGC models currently available. WOZ, TH, DI, MMR and AFMR all play a fair bit differently (and have longer ball times) from TWD and MET and would be a great combination as well as complimentary.
Quoted from T7:
Strongly disagree with TWD Pro being better than the Premium.
It is a good value, but the additions on the Premium are excellent IMO.
Yup, and after hundreds of reviews that the TWD LE/Prem model rates significantly higher than the Pro model here on Pinside; simply put, most people prefer the LE/Prem. The left ramp just isn't an issue at all for most people either. In actual play on both the Pro and LE/Prem, the right ramp will airball sooner and at lower speeds than the left ramp on the LE/Prem; so if one wants to talk about ramp problems it should start with the right ramp on both models. I've played both the Pro and LE/Prem and they are both great; I also agree with the reviews of most others here on Pinside..... that the LE/Prem is better than the Pro. And the LE/Prem is one of the most feature rich upgraded LE/Premium models ever made. It has it all for upgrades; art, PF changes and toys, GI and lighting, and even coding. A wicked cool combination.
There are many things to love about the LE/Prem. Guinnesstime is not alone with this recent feedback in the club thread.
Quoted from Guinnesstime:
Walker bombs are the bomb.
IMO anyone on the fence should get the premium. The ramp with the flap fix is perfect. The light show is amazing. Horde is one of the coolest pinball modes.