I'm judging by your tag that you want a power lifting barbell. I have no idea what your budget is, so I'll give you some brand names and some things to look at when comparing barbells.
First, brand names:
- Eleiko - their first love is Olympic weightlifting, but they make world renowned barbells.
- Ivanko - their first love is powerlifting, and they also make world renouwned barbells.
- Rogue - their first love is crossfit, but they have some very good barbells for better prices
- Pendlay Elite - first love is Olympic weightlifting, but also very good barbells for reasonable prices
There are other companies, but these will get you started.
Second, what to look for:
- You want barbells where the shaft is somewhere between 28.5 mm and 29.5 mm. Thicker barbells make it more difficult to get in a good position on squats and tax your grip more on deadlifts.
- The loading area should be 50 mm (roughly 2 inches), and it should spin
- For powerlifting, bushings are sufficient and for Olympic weightlifting, needle bearings are best
- Try to choose a barbell with the highest tensile strength you can afford (ability to snap back to true after the bar bends).
- Look for IPF or IWF compliance. Basically, they dictate what constitutes legal weight and knurl markings for the respective competitions. (IPF is for powerlifting and IWF is for Olympic weightlifting). All bars compliant will weigh 20 kg (about 45 lbs) and have compatible knurling.
Tensile strength is usually measured in PSI (pounds per square inch). Look for barbells with at least 155,000 PSI and if you can afford it, over 185,000 PSI.
If you are in America, the best value for your money is going to be from Rogue. They have a number of bushing bars with 185,000 PSI or better and a price range of around $250-375 USD for those barbells. Because of the volume of business they do and the fact that they are situated in the middle of the US, their shipping prices are among the best you can get.
In the US, mid-range barbells typically cost $250-$400 for bushing bars and $500-650 for bearing bars. If the Clean & Jerk, and Snatch are not your primary lifts, then consider bearing bars a luxury. However, if they are your primary lifts, consider it a necessity.
In the UK, it seems like the cost of all gym equipment has the same numbers, but it's in Euros or Great British Pounds. That means they cost twice as much as they would in America. It's not fair, but they guys I know who live over there have all reported the same things.
If you are elsewhere in the world, hopefully you can use this information to judge between the brands available to you where you are.