What are the best cartridge matches for Linn LP12?

I have a Linn LP12 with Basik Plus tonearm. Presently I am using an old (but in good condition) Grado G-1+ cartridge. I notice a little hum but otherwise I like the sound (balance, detail, warmth).

What are some great upgrade paths for cartridges from $100-300 (new or used)? How do different cartridge brands sound on the LP12?

I am using an old Dynaco PAT-5 modified preamp and a Dyanco ST-150 modified power amp. Overall I'm pretty comfortable with these for the time being.
I just put a new Linn Adikt ($300) on my LP12/Basic Plus. I like it a lot, without being able to compare it to many other choices. It's likely to be a little more vivid, and with a slightly leaner midrange than a Grado, but without the annoying hum problems. And, or course, it's meant to work well tonally and mechanically with the table and the arm.
I like the Goldring cartridges with the Basik tonearm. I am pretty sure that the Linn Adikt is a OEM version of the Goldring 1042. Audio Note also uses a OEM 1042 for their MM cartridge lineup. It is a good cartridge.
I might be more concerned with matching the cartridge to the phono preamp (or vise versa).
If you like the cartridge, you might get a newer Grado.

A used equipment dealer told me that his first choice today for a Linn would be a Shure V15--even though it's not trendy. I haven't heard this combination myself, although I have heard of people using it.

The one thing that I'd be cautious about considering a moving coil cartridge. I'm under the impression that, in general, moving magnet cartridges work better than moving coil cartridges on the Linn Basik. (A very arm friendly MC might be OK.) In addition, I'd check to make sure that the preamp you have can handle a MC.
I had a Basik + arm w/my LP12 and that arm mated well with a broader spectrum of cartridges than other tonearms.

The Goldring Erocica LX (low output) sounds amazing on it. The high output version has the same body shape and materials so you could probably expect similar results.

The Linn K18 was even more gorgeous but its out of production and impossible to find.

Actually if you listen primarily to modern-era rock and rock-based fusion the best budget cartridge for that combo might be the Audio Technica 120e (don't laugh: only $54 thru Garage-A-Records online)! I had one on that combo and it had an almost "master tape" feel to it in terms of the detail and bass energy. Subtle tonalities of low level instruments on classical records were a bit forced-sounding compared to the Goldring and K18, but still bearable.

Most important advice: remove that arm before tightening or loosening cartridge bolts. Linn arm bearings are very sensitive to this...its no joke. Deformed bearings will give you compressed imaging and distorted sound.