I was going to suggest Lisp and for me Forth is something I loath. I looked at APL once and burst out laughing. I find most languages I have used make for a love-hate affair.
"Assembler" I don't even know where to start because some are good while some are terrible; Microchip did a spectacularly bad job there for their PIC chips.
If I had to pick a single language to use it would probably be Python though there's a good deal I don't like about it.
The one with the Advanced Brainfuck Programming Manual in the pocket ->