Like the title says. I have no real preference towards brand. My cash limit is around 500USD. I was considering the Fender Stratocaster, being that it was played by my blues idol, Kenny Wayne Shepherd, and my favorite Jam Band guitarist Jerry Garcia. I'm willing to be talked out of it.
Freedom isn't free...

It costs like ten dollars a gram
I say try a few mex strats, find one you like and get it. You can always put a humbucker in if you want to get some different tones to what it offers. Semi-hollows are good for blues too, look at bb king, something like an es 335 clone. Saying that i have double cut les paul and that fills my blues needs. Theres alot of choice out there
Yeah something like a Strat, LP, or a hollow (semi- or full) body like a 335 would suit your purposes quite well. I agree with Xeus, look into MIM strats.
Only play what you hear. If you don’t hear anything, don’t play anything.
-Chick Corea
I've got a strat. I love it. It's a lot of fun and it hasn't shown me any problems. If you get one MAKE SURE IT'S NOT A BAD ONE. Do NOT get a cheap one that you'll regret buying. I'm not saying that you have to get the best one, but don't get the worst one.
My Gear:
Taylor 410CE
Fender Highway One Strat HSS
Egnater Rebel 112X
Egnater Rebel 20
Digitech RP350

Quote by VolumeControl
I once hypnotized my pet rock,. He just sat there...hypnotized out of his mind.
For your budget: definitely a Mexican Stratocaster. Either a HSS or SSS. Those are very versatile guitars and very suitable for blues and improvisation. I play on one myself and I play grunge/funk/(hard-)/(pop)rock/blues/etc on it. For superhigh gain I wouldn't get one, cause those Singe Coil pickups tend to get noisy at high levels of gain. But for anything else, you're in for a good ride
SSS MIM Strat all the way. As aforementioned, quality can be a bit inconsistent so make sure you play before you buy. You won't regret it, they are fantastic all-round guitars and if you're fave musician plays one then even better.

Neck&Mid position, tone rolled down a bit, tube amp = perfect
are you going to be using any effects? a slide? what amp do you have?
Quote by CoreysMonster
you know why rabbits are smarter than cows?

fucking cows start moo-ing around for no reason, but rabbits keep their mouth shut until they actually have something to say.

god I hate cows.