Soulcalibur IV

This is the 'Tower of Gold' achievement. You have to acquire over 1,000,000 Gold. It doesn't matter how much Gold you have spent. So you could get this achievement while you only have 1000 Gold as it counts the lifetime Gold you have earned.

NOTE: Just by playing through the story mode with all 34 characters you'l get nearly 500k towards this achievement, (if you manage an S rank you can get up to 16k per character, netting you a max total of 544,000 gold) You'll need to play through all characters anyway to obtain all weapons and items needed for Transcend history and the World achievement. This achievement doesnt require you to have 1,000,000 gold at ONCE! This can be obtained with any amount in your current bank as long as you have accumulated 1 million over the course of your playthrough.

Credit to Mideav and CHEW9190 for working out the amount gained via all 34 story run throughs!

For me, personally, without relying on the Algol glitch, the fastest way I could get gold (as well as working towards the all equipment achievement) was Tower of Lost Souls 11th floor, where all four enemies set themselves up for easy grabbing. Using Cervantes, the basic A+G grab can ring them out as soon as I push them towards the edge, which is not hard. Finish the floor in just a few minutes (or less if they're dumb) and it's 4500 gold. You can also complete the critical finish achievement on this floor by using Yun-Seong's forward Y, Y move incredibly quickly. Keep running to push them towards the edge and you also work towards the 10k m achievement. A lot of things can be done at once here.

As both other solutions say, this achievement does not require you to have 1,000,000 gold at once, however all together across your play time. In order to purchase all equipment, you will need 3 million so this will not be far out of your way if you are looking for completion.

A while back there was a patch to fix this trick, however it still works despite being a bit tougher. On the final level of the tower you face Algol in the usual final destination type arena. The trick is to get him to knock you down, and wait for him to do a jump attack over you, throwing himself off the ledge. This is a quick 10,000 or so and beats completing story modes/arcade mode as far as time is concerned, but as xeno said you will be just about half way there after completing all of the story modes.

If you wanted to, you could un-install the patch from your xbox and grind gold that way as it is a little easier to get him to ring himself out. Either way it's a bit of a grind but by no means impossible. Best of luck and enjoy spending the gold!

I find that the easiest way to grind the gold for this (and more notably Transcend History And The World) is to play Astaroth's story on Hard. Using his Down-back+X,Y maneuver more than handles the AI in mere seconds and nets you a whopping 24K per run, provided you get the S rank.