1) Medieval Knight
Gear: Knight Set (with Elite Knight Helmet), Longsword, Knight’s Shield.
Start as a Knight, choose the Master Key. Go through the Valley of Drakes, rest at the bonfire and get the Elite Knight Set in Darkroot Garden. Get to Andre, buy the longsword and get the Knight’s Shield in Undead Parish.
2) Samurai
Gear: Eastern Set, Uchigatana, Longbow.
Any dex class, master key. Kill the merchant in Undead Burg, use the master key to open the tower basement, run up the cliff in Darkroot Basin, get the Longbow. Go towards the waterfall, climb the ladder, get through the forest until you find an open space with many plant enemies, get the Eastern Set.
3) Ninja
Gear: Shadow Set, Iaito, Bandit’s Knife
Start as Thief, open the Blighttown shortcut, get down to the swamp staying close to the bankside, go forward until you find other plank buildings, get the high ground (very hard) until you find the bonfire. From here climb up, get the Shadow Set, climb again, jump on a wide platform and get the Iaito.
4) Viking
Gear: Chainmail Set with Royal Helm, Battle Axe, Caduceous Round Shield.
Start as Bandit, get the Firebombs in the Shrine, get the Caduceous Round Shield in the graveyard, get down to the Catacombs, pull some levers, dodge the skeletons and get down the first hole without dying. Lure a Bonewheel in to kill Vamos (use the Spider Shield to block) and get the Royal Helm. Get back to Firelink Shrine, go to the Burg and get the Chainmail Set.
5) Spartan Warrior
Gear: Balder Armor and Leggings, Brigand’s Gloves, Partizan, Spider Shield.
Bandit, Master Key. Get to Darkroot Garden, get the Partizan. Get to Undead Parish, farm Balder Knights for armor pieces (use humanity to raise discovery rate). About 10-20 minutes later you’ll have a King Leonidas look-a-like right away.
Now you can easily customize these builds and use different weapons or armors, but if you want some right away