What’s the best vacuum cleaner for under $200?

Being newly married and in my early twenties, I have NO idea what to look for in a vacuum. But being the thrifty shopper that I am, I thought I was getting a really good deal when I purchased my current DirtDevil UltraVisionTurbo upright vacuum for at Walmart. But after only having this vacuum for about a year and a half it now leaves NOTICEABLE amounts of dirt behind, no matter how much I empty the cannister out and clean the filter. I’ve even had to take the whole thing apart and clean out the tubes that continue to get clogged up and spew dirt out as I vacuum. So…I don’t want to spend a lot of money, especially during this holiday season, but I also want to buy something that is going to last a while. I’m wanting to stay in the 0 or less price range. Any suggestions (please also include website or store-name where it can be purchased)? I am mostly looking for a vacuum that will work on short-medium carpets, that has a bagless feature, and has a good filtration system since my husband and I have horrible allergies. THANKS!!!