Seminole or a duchess, parts availability, they are "easier" to insure because there are tons out there, and very common trainers. If this is a plane you are looking at using in the future for traveling, a C310 is a plane I've heard of folks training in, but it'll cost a lot more to operate(trade-off is that it's very capable, but if you're not using it sooner than later, would be a bad choice).
I have a soft spot for C310's as 2000hrs of my total time is in them, but I don't know how well I'd trust zero-time folks learning in them. Trade-off being is that when they learn in a plane like a C310, they will actually appreciate critical engines, and get some solid high-perf time.