Hi GuruSY,
I know exactly what you're talking about for graphics. There is a slight difference between the Diablo and BG graphics styles. They're both a top-down view, but if you pay attention you'll see that characters in Diablo can only move in eight directions (N,NE,E,SE,S,SW,W,NW). This is ahieved by using a 2D art program like Paint Shop Pro, Photoshop, or regular old MS Paint (which could be more difficult than others).
In Baldur's Gate the characters have free rotation, which either means they have a cool way of manipulating 2d images, or they used a 3d modeller. Using a modeller from here such as gameSpace(which I highly recommend) allows you to create a 3d character you can twist and turn in whatever direction you want. This could allow you to do a game with art similar to Dungeon Siege or Neverwinter Nights with Baldur's Gate or Diablo style gameplay.
Some 2d Programs:
Paint Shop Pro 8-powerful but relatively affordable, $70-$100
Adobe Photoshop-big grandaddy of 2d, but $500
MS Paint-free probably came standard with your computer, but limited
GIMP- the Free Software Foundation's solution for 2d
Some 3d Programs:
gameSpace- gamemaker's ideal version of Caligari's TrueSpace, $300
nice interface
3d Canvas Pro-affordable, but could be difficult to use and a
little limited
3d Studio Max-professional grade, expensive $3500
Maya- better quality than 3d Max, and $5000
Lightwave-still high quality, but cheaper than 3d Max, $1500
Milkshape3d- powerful for only being $25, RPGamer can tell you all
about this one
Anim8or- free, but can difficult to learn, and a bit limited
trueSpace3.2- now free, but very limited, gameSpace is based off
this interface, it's a nice interface, just limited
DeleD- a rather nice free 3d modeller written by a cool guy you can
findround here
JT Edit- like DeleD, a pretty darn good free 3d modeller from a guy
within these forums
Wings3d- a free and pretty powerful modeller, but no animation
Blender3d- this is very difficult to learn, but has everything you
need
gmax- free, mainly used for mods, but you can export unanimated
models to a .md3, and then convert to .x
3d Exploration- General graphics view and converter
MatEdit- Creates and edits matrices, the terrain format DarkBASIC
uses, MatEdit has a tile per tile editing system
MagicWorld- A matrix editor that allows you to place 3d objects onto
matrices and has a mouse-dragging interface like most
scenario editors for pc RTS games
And that's about all I can think of for now.
Good luck, keep asking questions,
Crazy Donuts
[EDIT]Sorry bout that Lord Helmet, posted at the same time.
Juvenile Industries
Current Project: KillZone(FPS)
Soon to come:An rts, and a snowball fight game