I have a brown sofa, light oak floor, blue floral accented curtains and sea foam walls, white ceiling, with creamy/ white trim. I have no idea what i should do i have a burgundy and cream shag rug that's kinda a woven pattern that i think looks good but i don't have a very good eye for matching colors.
Beige, try it, I just bought one for my room.
If you don't want to go out looking for a new rug, I would use the burgundy and cream one and just go out looking for a few inexpensive things that could tie together the burgundy, cream, and blue. But if you are looking to buy another rug, I think matching your curtains is a good idea, or going for a neutral color might be even better in case you later decide to redecorate, as neutrals will match most anything. Maybe you could go for a cream or brown? There are tons of rugs that have browns, creams, and blues, especially in florals, all together. Brown and blue can be very pretty together, and maybe even cute or trendy, so I'm sure you'll find something :) Best of luck to you.
Since you have several colors in the room already, I think a rug with a brown and blue pattern to match the sofa and curtains would look better than the burgundy. If you have too many colors in a room, it looks unplanned, and just thrown together with whatever you happened to have. What I would do, if this were my room, would be get rid of the blue curtains, since they don't match anything else. They're easier to replace than the sofa, or to paint the walls. Then look for curtains and a rug in brown and seafoam, or brown and white.
Just make sure it matches the drapes.