Quoted from FatPanda:

There's an IM at Maria's on East Wash that you can play on route. According to pinball maps, there's an Xmen Pro you can play at Up North downtown. I haven't been to Up North yet, so i cant confirm that its there or that its well kept, but IM is for sure at Maria's. Whats your other pin and will it be similar to either of these?

Quoted from Audioenslaved:

I have woz, IM and Xmen. Love them all. IM I love for short fast and hard! Xmen I love for depth and hardness. I've never reached Xmen wizard modes

Quoted from taylor34:

The games you've owned sounds a lot like the games I've gone through. I have STTNG, have owned Stargate twice, bought IM NIB, and have X-Men pro. I sold IM earlier this year after owning it for 6 years because I was ready for a change, but kept X-Men because it's still a really fun game. I don't think you can really go wrong with either, but they're totally different games. Iron Man has very short games, X-Men is mode based and is pretty long.

Quoted from Jediturtle:

Hmm...that's a really tough one. I have a IM Vault and X-Men Wolverine sitting right next to each other. I'm not sure I could pick one over the other. They are very different games. As others have mentioned, IM is fast and brutal. The rules are very straight-forward and it is not very deep, but that fits the playfield very well. The layout and code mesh perfectly. It is one of the highest adrenaline, one more time games ever. X-Men is much deeper with more toys/gimmicks and many different ways to play. I find it to be a difficult game also...I've never had the 30 minute games mentioned here, but it is more forgiving than IM. For me the LE is a must...I love the Nightcrawlers, spinning disc, and color changing GI, and am fairly neutral on the moving ramp. I can see why some prefer the pro, but for me the extras really make the game shine.
So I guess I am really no help. Both are fantastic games and two of my all time favorites. If forced to choose, I would probably go with X-Men for the better art, more to do (code and layout), and fun toys. But it's very, very close.
Play them both, see which one grabs you hardest. If you ever make it up this way, you are welcome to play mine.
As for Hobbit...no. Just no. Terrible game in my opinion. Beautiful with impressive technology...but oh so boring. It's the polar opposite of IM and XM.
Good luck! Really at the end of the day, there is no wrong choice here...they are both awesome games.

Quoted from Jediturtle:

One other thing...I just saw that your other game is Metallica. That makes me hesitant to recommend IM as the playfields have many similarities. Do not get me wrong...they play very differently, but the geometry is very close. X-Men is quite different, so may be a better choice in your 2 pin collection. Otherwise have you thought about Spiderman? It has a lot of similarities to ST, which you enjoyed, but with a theme that might be more towards your family interests since you are looking at other superhero pins. Just a thought!

Quoted from HoakyPoaky:

I think you answered this yourself. If you haven't played a pin firsthand, then there's no guarantee you will like it. Go play XMen & form your own opinion before making your decision.
For me it's a no brainer. IM all the way. I think it's a Top 5 all time pin. But I enjoy games that are brutally hard & keep me coming back for more. IM is lightning fast & fights back the whole time. The ruleset is simple yet difficult to master. It's a great multiplayer game due to short balltimes. Great callouts, great sounds. Borg design, Lyman code = winner every time.
Very addictive, very frustrating = hit the start button one more time. I love games like that. Then when you finally hit your goal after many attempts (like hitting the DOD hurryup), you feel like you really accomplished something!

Quoted from PersonX99:

IM is closer to MET than XM. IM is BRUTAL, but the rules are simple and the game becomes more about skill with speed.
XM is much deeper, but as someone pointed out, the games are longer.
I own both, and play them, depending on what I am in the mood for at the time.
Of course....you could get both and call it a day... :p