I'll be honest, as honest as I can be.
In terms of overall 'better' then the list should go as follows: 3, 1, little m, 4, 2.
Why?
3 is by far the superior game in many respects, it has the most responsive combat, the best presentation, the right amount of story and difficulty. In these respects DMC3 is still the unmatched entree that raised the bar in this genre. The design shows more thought and balance than most other entrees in the franchise and has, by far, the largest arsenal in the DMC brand. For all it's limitations, such as no on the fly style switch or having to find a statue to switch you're weapons, and not that many combos per weapon, it still provides the challenge and freedom that every title after has tried to match and other copy.
DMC1 might not have the combat that all of it's sequels have but it provides an experience that has never been matched by them. This game has crunchiest combat in the series, every time you end a combo there is power behind it and, yeah, sure, every game's stinger makes a rumble but here it makes real a, earth shaking, quake; The impact of each end of combo really gives you a sense of power and strength behind them. Then you have the ambiance and tone of the game which really show it heritage as a horror survival title, something every game since has abandoned but sets it apart to the rest. With the best BGM (songs don't count) and the most memorable rendition of Dante this game still delivers, despite the aging and cobwebs it's gathered over the years.
DmC tried and and made advancements in many areas but unfortunately it made improvements from DMC4, which is not the best place to start from. DmC's combat is fair step forward from DMC4's, it's tightened and with the help of the grapples it helps build bigger environments with out sacrificing flow and strategy, it takes the best of Nero and Dante and blends them together well. The issues it has, however, are just too many to be overlooked and keep it from been a better game. It's not all bad, in fact there is plenty of positives, however, the negatives just out weight them by a fair margin and will keep it from ever been as good as 3, and worse still, it doesn't think it is.
DMC4 is just boring. It's a safe game that takes no chances and wants to appeal to as many people as possible. With a philosophy that starts with a new protagonist to draw in a new audience and ends with the removal of anything that might scare away girls this game's pro's just don't justify the con's. Nero's story and combat are just meh, a mixture of blandness and safe egg shell walking. He breaks no barriers in ether department and does nothing but the delude the presence of Dante as a unique individual. Dante's only addition here is on the fly style switching, and that doesn't exactly do much since it's still not as good as DMC3. meh, story, meh combat, and the only good things about it came from DMC3. Well, at least it's pretty.
DMC2... Do I really have to say?
That is what I think is the most 'fair' take on this. my personal list, however, is a tad different. It goes like this: 1, 3, 4, little m, and 2.