Yo, looks like you’re into gaming.
Someone made an air purifier similar to a gaming PC chassis. Using a special metal case and with space for filters. About as good performance as the box fan/filter abomination but with easier replaceability.
Pretty sure you can find a place for rgb fans too. https://housefresh.com/nukit-tempest-review/

I’ve been happy with Coway.

I have the round IKEA one, works fine.

https://housefresh.com/ Because: https://www.youtube.com/watch?v=5gNLViWfCA0&t=937s

I’m really happy with the one from IKEA, the bigger rectangular one. I’ve had it over a year. Not the prettiest, but if you don’t dislike it it’s alright

On mobile so won’t grab all the links, but I’ve done a lot of research into air purifiers and can echo what most people said

• Most air purifiers over 50$ are as good as the ones that sell for 150$+
• I personally buy Winix
• An air purifier can clean a room in 1-3 hours, but since I’m paranoid I keep mine running 24/7
• Don’t buy anything over 100$, it’s not worth it (if you want super clean rooms, buy one for each side of your house)
• Clean your air purifier (just wash the filter) every month or two (there’s a lot of dust it traps)
• Enjoy the investment, air purifiers are great!

Depending on your needs, if you want the most effective filtering for the price (though at the cost of noise) you could make your own https://en.wikipedia.org/wiki/Corsi–Rosenthal_Box . I built one and found it to be great, but I did end up buying a commercial one through Costco years later.

• One important metric: m³ / (hour*$), so how much it can filter for how much money
• Also the volume on the setting that gives the filtration power needed. Often it is best to get a bigger one, run on middle or low level, especially for office or bedroom.
• How much m³ / hour overall? When it is against dust, allergens, pm2.5 etc., filtering your room volume once per hour is decent. To protect from viral infections, e. g. at a dentist or doctor, 6x the volume of the room is ideal. For private use, it’s nice when it can do once per hour on a lower setting, and for occasional parties 6x of that on a high, loud setting to avoid spread of viruses.

Pretty good for your money is the Corsi-Rosenthal Box mentioned already. As for things that don’t require assembly, Trotec beats all prices in Germany, e. g. the 250E or 350E: https://de.trotec.com/shop/design-luftreiniger-airgoclean-250-e.html That would provide more than you need for typical home use already. For a single room such as your bedroom, you can get something really decent for less than $250.

The ones that are below HEPA standard are not as bad as somebody mentioned, imo. Against many things, such as dust or allergens, they should be fine. I’m buying only HEPA filters myself, though; doesn’t really save much otherwise.

I use an older model that’s kind of like this one.

https://a.co/d/eIMfMtB

Tis HEPA, but I’m sure you could get the same effect for cheaper. That said, I’ve been happy with mine for about 4 years now.

Sharp

I’ve been using a blueair one for a couple years

I got a 20-in box fan and four 20x20x2 air filters.

Tape the air filters together into a square and then tape the box fan on to one of the open sides.

Said it so the box fan is facing upward, plug in and turn on. You have a whole house air filter for like $50 or less that will do as good of a job if not better than pretty much any other device on the market.

When the air filters start to turn a dingy color, replace them for 20ish dollars. Fan should be good for several years.

I like our Honeywell Insight. Looks OK, is quiet enough and most importantly: Has readily available generic HEPA filters. I use it for fire season, it makes a noticeable difference to me re: wildfire smoke in my house.

Whatever you buy, make sure to remove the plastic wrapper of the filter before use.

Ask me how I know

What are you hoping to filter with it? I have a general purpose Honeywell Insight, it works well enough for my allergies and pet dander in my apartment. I think I paid something like $200 for the unit 3 years ago, but filters are $85 a year for it - pricey but they’re widely available.