Modern interpretations of the medieval sword have become abundantly available in the past few decades as elements of garb (costume) for members of organizations such as the Society for Creative Anachronism and re-enactment groups worldwide, as wall-hangers and as collectibles in their own right. The quality (and price range!) of such swords varies greatly and price is not always in direct proportion to quality. Too often the designers of such items base their work upon fanciful illustrations in Victorian era books or poorly researched Hollywood adventure films, and as a result, much of their product is nauseatingly ornate and unwieldably heavy. As a generalization, actual medieval swords were tools capable of being used for a rather grim purpose and represent, for their time, an object at the cutting edge [pun irresistible] of materials technology. (This is not to understate a non-cutting role for swords in antiquity; some of the best Viking swords are from rich farmer's graves in upland Scandinavia, far from the sea, and the presence or absence of a sword at the side could be a reliable clue to social status, distinguishing master from slave at a distance. Nor can I deny that some of the princely swords of the Migration Period and a minority of Viking swords have hideously ornate hilts when compared to their more austere successors, or that I am prejudiced in this matter by my personal tastes.) While some manufacturers are wising up to the wide range of splendid designs in the public domain which evolved under test of battle in antiquity, the majority of swords in most maker's catalogs have no counterpart in the actual swords of the Middle Ages, or of whatever age they purport to be inspired by. I do not think I am giving away anything obvious to say that, while the outlines of actual swords and their dimensions in face-on view are easily obtainable, the really critical data for the modern replicator wanting to get the right feel and function are the measurements and topography of the third dimension.
While knowledge of modern science and access to modern metalworking technology should permit manufacture of blades of a quality substantially superior to that achievable by the master swordsmith's skills in medieval times, I am told (by a consultant to the cutlery industry) that this has not been the case in practice. Instead of being forged of many rods and strips of iron and steel (swordsmiths before the Thirteenth Century having had no other option) a modern industrially produced blade is likely to have had its blank outline roll-forged or stamped out "cookie cutter" style from uniform sheet stock with the fullers, bevels and tip later formed either by grinding for those made in the "first world" or hand-forging for those made in the "third world" where skilled labor costs are minimal. Compromises in accuracy of reproduction may arise more from trade-offs allowing fast easy production than from ignorance of historical forms. To achieve a high performance blade requires the combination of a tough steel and rigorous heat treatment, however, such a combination is rarely seen in modern swords except for high end Japanese style blades specifically made to withstand the rigors of tameshigiri (test cutting). Most European medieval style swords made today are intended as costume accessories and wall decorators and are not intended for actual combat (read the warranty disclaimers) and the industrial solution in actual practice is to use an easily worked low to medium carbon steel or stainless steel and to give it gentle (low stress) heat treatment, if any. The result is that the poorer quality sword shaped things will unpredictably bend or shatter when stressed.
This is not to imply that the better grades of modern medieval European style swords are that much worse than the antiques, it is just that after a millennium of scientific advance, they are not really much better. If you were to use an antique medieval sword as depicted in movies and on television, it would rapidly and likely catastrophically fail. Edge to edge contact that works with aluminum alloy sticks does not work with steel edges. Descriptions of invulnerable swords in the sagas may be legends you will wish to ascribe to literary license or mythology, but when the sagas describe failures of swords, these parts should be believed. Viking combat generally involved a large round shield with an iron rim and shield boss. Striking this would have been bad enough for the blade, except that the resiliency of the shield bearer's arm would absorb much of the energy of the stroke rather than the edge of the blade. Leather or fabric wrapped legs were a favored target in these times, as the torso would be reasonably protected by chainmail with underlying padding and the head by a helmet.
My advice? Believe few of the claims of the replicators. The ancient swordsmiths made (and some modern artist-bladesmiths currently make) swords at the limits of their skill and their society's knowledge; however, the usual limiting factor today is to hold costs down low enough so that suppliers can make a reasonable profit while selling you a sword shaped object at a price you can afford. My prescription for improvement? That we be discerning and demanding consumers.
With that said, a vast panoply of modern interpretations of the medieval sword are presently available worldwide to fulfill virtually any imagined need. Considerations of which model and brand or manner of manufacture are best for martial arts uses are beyond the scope of this website, which is focused on antique swords, and readers are referred to the links page for sources of such information.