FW-190 & BF-109 1/48 best kits

Hasegawa, with Eduard close behind.

Hasegawa has a wide array of those two subjects.  They are kinda slack on details tho.  The Eduard kits have better surface detail but their FW-190 kits are very tricky to build and they tend to have soft plastic so thats the tradeoff.  But the Eduard kits tend to be cheaper than the Hasegawa kits though and you get the masks and PE fret which is nice.

Eduard is about to release their Bf-109G Royal Edition which will have 2 kits lots of detail and some extra goodies in a couple weeks :)

Ditto on the Eduard 190's being "tricky"

If you settle on a 109 F The Svezda F2 and F4 are tough to beat.

There's been a lot of flack on Eduard's newest Bf 109s due to being too long or too short. I have Hasegawa's Bf 109 G-6.

The Eduard 109Es are absolutley one of the best kits on the market (In my opinion at least).  They just released a G model 109 but It's been getting some flack for being a bit over scale.  They're 190s build up nice and have far more detail than Hasegawa's offering but that comes at a price.  Their build is so finicky that if you're off by a hair at any point during the build the rest of the model will fight you.

Quick addendum, if you're looking for PE and other goodies look for the Eduard Profil Pack versions.  They come with color PE and canopy masks.  Sometimes they'll also throw in their Brassin resin updates like wheels.  

Unless I missed it, no one mentioned the Tamiya Emil, which is a fantastic kit.  For the 190 and 109 above the Emil, It has to be the Hasegawa kits which are a nice balance between detail and engineering.  In my opinion, the Eduard 190's look the best regarding surface detail, but they are a major PITA fit-wise and aren't work the aggravation.  

Joe

Joe if you missed a mention of the Tammy E's so did I.  And I have 2nd your opinion... very nice kits indeed.