uh well none are particularily easy to upgrade. the wep i used and upgraded during single player village was, i think, a lance. i got the spiral lance because most of the bosses are weak to water. if your going to get a gs (great sword) the best bet is to get giant jawblade and get upgrade it to the rathalos firesword. switch axe would be bone axe at first if you like them. longsword the first you get is ananta boneblade and its pretty good seeing as it has paralyzing element. i dont like sword and shields so im not gonna tip you on those. i use bowguns only regularily.and hammers, i would get the peco flint and keep ungrading till you get the rathlos hammer.