Out of the ones you mentioned, it's hard to beat a Springfield or Mauser for "traditional" usefulness or appeal. Unaltered they still feel more like a modern rifle (probably because most modern rifles are based on variations of those actions).
The Lee Enfields are cock-on-close, rimmed, have a huge protruding magazine, and a two piece stock. The integrated peep sight on my No4 Mk1 certainly is neat, but it's a bit of a novelty rifle for me. I know one guy who shoots a scoped/restocked sporterized SMLE, and it does fine as a hunting rifle (certainly nothing wrong with the cartridge's ballistics). Just wouldn't be first on my list. I think I paid $79 for my SMLE from Centerfire Systems. It's the most beat-up looking Milsurp I own (and that's after spending 3 hours cleaning it up
), but it still is in perfect working order mechanically
.
The Schmidt-Rubin K31 is also kind of a novelty (got mine from AIM back when they were $89). Straight-pull bolt, unconventional (but very reliable) safety, top-eject. I like mine, but again, it's a bit of a novelty. I will say that with iron sights this is probably the most accurate milsurp rifle I own.
Mosin Nagant. They're dirt cheap right now (have been for a while). I paid $49 for my m38, and I certainly don't regret it. You almost owe it to yourself to buy one of these things
. But, if it hadn't been so cheap, I wouldn't like it. Overall, I just don't like the Mosin Nagant action. The magazine well is single-stack and so protrudes way down, the cartridge is rimmed, the bolt is complicated and has a very difficult to use safety (similiar in design to the K31's but not nearly so elegantly implented), and the action is "clunky" (bolt handle is far forward and must pass through the rear receiver bridge). The stock is also just not comfortable to hold. Again, given their price, you should definitely get one, but if it's a "I can have only one" deal I certainly wouldn't take a MN as my only milsurp.
Springfield 3040 (I assume you mean the Krag-Jorgensen? - not sure) - I don't own a US Krag, but I do have a Norweigan Krag in 6.5x55. Personally, I think these things are a very, very neat little action. It might have sucked for military loading, but that side box is pretty nifty in my mind if you're not in a hurry. Krags tend to be expensive in complete condition though, so I'd go for a Springfield 1903 (or A3) first before buying a Krag.
My order, from most desirable to least, if price was the same for all, would be: 1903, Mauser, Krag, K31, SMLE, Mosin Nagant.
But since price likely not the same on all, I say get the Mauser
. Yugo M48's and M48A's are still reasonably priced (I think), and there might still be some cheap Turk's hanging around. I've got an all matching M48A that I paid $69 for from Sarco, and a $59 Turk in very good condition (extremely smooth bolt on this one) from SOG. If it's not a wife or something laying down the line then for that $180 you could almost certainly afford both a Mauser and a Mosin . . .