We liked Rosen inn pointe Orlando for the price.
Agree look for a deal - groupon or travel zoo are worth checking.
Rosen Inn at Pointe Orlando is great value if you can get it for £30-35/night (you can get it for less than that if you're lucky!). Fantastic location as you will then be able to walk to restaurants, bars, shops, mini golf etc. which is nice - probably the best location on I Drive. It has 3 pools, which are well kept though shade is limited we found (fine if you like to crisp in the sun like me, not so good if the heat bothers you...). Fridge and microwave in the room too. It's also handily opposite a 24 hour Walgreens for drinks, snacks etc. Staying again this year. Downside is that the resort is pretty big and reception/cafe/shop etc. is all at one end of the resort, not central, so you can be a good 5 minutes walk out (personally that's fine for us since we go to reception to check in/out only!). We heard a lot of people complaining about it whilst we were there, though. Oh, and I sent my partner to get an ice cream and it was so far for him to walk back the ice cream was melting when he got back to me at the pool, so I had to wolf it down - woe is me

It's really, really popular though - over 1000 rooms and sold out often. It's one of the hotels Virgin use on their package deals, we spotted lots of Brits...
We have also enjoyed the Four Points Studio City in recent years - location not as good as the Rosen Inn at Pointe Orlando being further up I Drive but rooms and pool much nicer. Really close to Universal. Used to be able to get it for around £40/night but last year they wanted £90+ (not worth that!). They were doing some of the rooms up so I think they're trying to charge more for us (though we had a "new" room each time we stayed and it was nice but not worth £90/night!). I'd pay up to £45/night, maybe £50/night. Doesn't have fridges and microwaves like the Rosen though, boo.
The Doubletree is nice, good location but would only want a tower room myself.
If you're on a REAL budget, I have stayed at some really, really cheap places. Some lovely (seriously!), some meh, none awful....but not 3*.
Haven't stayed myself but you can get some good deals on the Hilton at Destination Parkway (£60-70/night).