*Beware, long post ahead*
I've been to a couple of tuitions during form 6. It's not a must but it really helps (We've been spoon fed since primary..so yeah :p) I'm going to recommend a few tuition teachers who taught me, whether you think if the teacher is good/bad, try it out and see for yourself :)
MUET - Many have suggested Mr Murugan in Kasturi (I've never taken any MUET tuition before so I cant comment on this, but generally there has been a really positive feedback from my friends and juniors who were taught by him)
BIO & CHEM - I took Mr Lingam's class in Kasturi for both Bio and Chem. (His classes are really good and informative.He's really good in teaching...oh and don't get me started on his seminars before STPM (EVERYTHING he spotted was IN !!!!) I remember all of us came out of the exam hall beaming with smiles from ears to ears and thanking him for that. [We used to secretly name him the walking & talking dictionary,because he seems to know everything] But there's one setback in his KL Kasturi tuition. The class is TOOO BIGGGGGG !!!!! He conducts his own Bio & Chem tuition in Subang as well, there's only one or two classes and the seats are limited (25 per class) Personally, I prefer his Subang classes, its smaller and its easier to concentrate (Kasturi has this weird ritual of staffs coming in the middle of the class to take the attendance and it will take at least 15 mins every time) His Subang classes are a bit more expensive, also because there's many extra classes throughout (RM80 single subject and RM140 for both) but its really worth it. I know he's conducting lower sixes class from the 1st Sunday of June (2pm to 6pm for both subjects) Those who are interested in Subang classes leave a comment/drop me an email. I'll send you his number so that you can call him to further confirm it.
PENGAJIAN AM - I never took tuition for Pengajian Am also. My school teacher is really good, also I never thought its necessary. BUT I went to Yakin's seminar for crash course. Its about hundred plus I think (I cant remember the price because its just once all but its a few day's seminar, so quite worth it) Plus the notes he gave during the seminar is good for revision. I've also heard some pretty good feedbacks on Mr Thiaga Kolej Bandar (can give a try if you want to take PA tuition)
MATHS T/S - I took Maths T under Mr Ong in Edusmart tuition. Its around RM90 per month. He also teaches in Kolej Bandar. I'm not too sure about Kolej Bandar's price. Can anyone let me know so that I can post it up? Mr Lingam was our god of Bio/Chem, Mr Ong was our god of Maths. (We really worship our tuition teachers haha) He's really good in teaching Maths, very patient. His questions are really good and he's very detailed in teaching. I always went up to him with my Maths homework half way done because I was stuck and I didn't know how to continue (I've not gotten his permission to post some of his questions here, so I can't do so until he agrees) Also, if anyone wants Edusmart's phone number for further enquiries, please leave a comment/drop me an email. I'll let you know :)
ps: I'm not paid for recommending the teachers. Its just my 2 cents opinion :)
**update: Mr Lingam's Subang class has moved to Kelana Jaya