I like using awesome_print for this. As a bonus, it gives you colorized output, method arity and where they come from:
1.9.3-p125 :001 > require 'ap'
=> true
1.9.3-p125 :002 > ap 5.methods; 0
[
[ 0] !() Fixnum (BasicObject)
[ 1] !=(arg1) Fixnum (BasicObject)
[ 2] !~(arg1) Fixnum (Kernel)
[ 3] %(arg1) Fixnum
[ 4] &(arg1) Fixnum
[ 5] *(arg1) Fixnum
[ 6] **(arg1) Fixnum
[ 7] +(arg1) Fixnum
[ 8] +@() Fixnum (Numeric)
[ 9] -(arg1) Fixnum
[ 10] -@() Fixnum
[ 11] /(arg1) Fixnum
[ 12] <(arg1) Fixnum
[ 13] <<(arg1) Fixnum
[ 14] <=(arg1) Fixnum
[ 15] <=>(arg1) Fixnum
[ 16] ==(arg1) Fixnum
[ 17] ===(arg1) Fixnum
[ 18] =~(arg1) Fixnum (Kernel)
[ 19] >(arg1) Fixnum
[ 20] >=(arg1) Fixnum
[ 21] >>(arg1) Fixnum
[ 22] [](arg1) Fixnum
[ 23] ^(arg1) Fixnum
[ 24] __id__() Fixnum (Kernel)
[ 25] __send__(*arg1) Fixnum (BasicObject)
[ 26] abs() Fixnum
[ 27] abs2() Fixnum (Numeric)
[ 28] ai(*options) Fixnum (Kernel)
[ 29] angle() Fixnum (Numeric)
[ 30] arg() Fixnum (Numeric)
[ 31] awesome_inspect(*options) Fixnum (Kernel)
[ 32] awesome_print(object, *options) Fixnum (Kernel)
[ 33] between?(arg1, arg2) Fixnum (Comparable)
[ 34] ceil() Fixnum (Integer)
[ 35] chr(*arg1) Fixnum (Integer)
[ 36] class() Fixnum (Kernel)
[ 37] clone() Fixnum (Kernel)
[ 38] coerce(arg1) Fixnum (Numeric)
[ 39] conj() Fixnum (Numeric)
[ 40] conjugate() Fixnum (Numeric)
[ 41] define_singleton_method(*arg1) Fixnum (Kernel)
[ 42] denominator() Fixnum (Integer)
[ 43] display(*arg1) Fixnum (Kernel)
[ 44] div(arg1) Fixnum
[ 45] divmod(arg1) Fixnum
[ 46] downto(arg1) Fixnum (Integer)
[ 47] dup() Fixnum (Kernel)
[ 48] enum_for(*arg1) Fixnum (Kernel)
[ 49] eql?(arg1) Fixnum (Numeric)
[ 50] equal?(arg1) Fixnum (BasicObject)
[ 51] even?() Fixnum
[ 52] extend(*arg1) Fixnum (Kernel)
[ 53] fdiv(arg1) Fixnum
[ 54] floor() Fixnum (Integer)
[ 55] freeze() Fixnum (Kernel)
[ 56] frozen?() Fixnum (Kernel)
[ 57] gcd(arg1) Fixnum (Integer)
[ 58] gcdlcm(arg1) Fixnum (Integer)
[ 59] hash() Fixnum (Kernel)
[ 60] i() Fixnum (Numeric)
[ 61] imag() Fixnum (Numeric)
[ 62] imaginary() Fixnum (Numeric)
[ 63] initialize_clone(arg1) Fixnum (Kernel)
[ 64] initialize_dup(arg1) Fixnum (Kernel)
[ 65] inspect() Fixnum (Kernel)
[ 66] instance_eval(*arg1) Fixnum (BasicObject)
[ 67] instance_exec(*arg1) Fixnum (BasicObject)
[ 68] instance_of?(arg1) Fixnum (Kernel)
[ 69] instance_variable_defined?(arg1) Fixnum (Kernel)
[ 70] instance_variable_get(arg1) Fixnum (Kernel)
[ 71] instance_variable_set(arg1, arg2) Fixnum (Kernel)
[ 72] instance_variables() Fixnum (Kernel)
[ 73] integer?() Fixnum (Integer)
[ 74] is_a?(arg1) Fixnum (Kernel)
[ 75] kind_of?(arg1) Fixnum (Kernel)
[ 76] lcm(arg1) Fixnum (Integer)
[ 77] magnitude() Fixnum
[ 78] method(arg1) Fixnum (Kernel)
[ 79] methods(*args) Fixnum (Object)
[ 80] modulo(arg1) Fixnum
[ 81] next() Fixnum (Integer)
[ 82] nil?() Fixnum (Kernel)
[ 83] nonzero?() Fixnum (Numeric)
[ 84] numerator() Fixnum (Integer)
[ 85] object_id() Fixnum (Kernel)
[ 86] odd?() Fixnum
[ 87] ord() Fixnum (Integer)
[ 88] phase() Fixnum (Numeric)
[ 89] polar() Fixnum (Numeric)
[ 90] pred() Fixnum (Integer)
[ 91] private_methods(*args) Fixnum (Object)
[ 92] protected_methods(*args) Fixnum (Object)
[ 93] public_method(arg1) Fixnum (Kernel)
[ 94] public_methods(*args) Fixnum (Object)
[ 95] public_send(*arg1) Fixnum (Kernel)
[ 96] quo(arg1) Fixnum (Numeric)
[ 97] rationalize(*arg1) Fixnum (Integer)
[ 98] real() Fixnum (Numeric)
[ 99] real?() Fixnum (Numeric)
[100] rect() Fixnum (Numeric)
[101] rectangular() Fixnum (Numeric)
[102] remainder(arg1) Fixnum (Numeric)
[103] respond_to?(*arg1) Fixnum (Kernel)
[104] respond_to_missing?(arg1, arg2) Fixnum (Kernel)
[105] round(*arg1) Fixnum (Integer)
[106] send(*arg1) Fixnum (Kernel)
[107] singleton_class() Fixnum (Kernel)
[108] singleton_method_added(arg1) Fixnum (Numeric)
[109] singleton_methods(*args) Fixnum (Object)
[110] size() Fixnum
[111] step(*arg1) Fixnum (Numeric)
[112] succ() Fixnum
[113] taint() Fixnum (Kernel)
[114] tainted?() Fixnum (Kernel)
[115] tap() Fixnum (Kernel)
[116] times() Fixnum (Integer)
[117] to_c() Fixnum (Numeric)
[118] to_enum(*arg1) Fixnum (Kernel)
[119] to_f() Fixnum
[120] to_i() Fixnum (Integer)
[121] to_int() Fixnum (Integer)
[122] to_r() Fixnum (Integer)
[123] to_s(*arg1) Fixnum
[124] truncate() Fixnum (Integer)
[125] trust() Fixnum (Kernel)
[126] untaint() Fixnum (Kernel)
[127] untrust() Fixnum (Kernel)
[128] untrusted?() Fixnum (Kernel)
[129] upto(arg1) Fixnum (Integer)
[130] zero?() Fixnum
[131] |(arg1) Fixnum
[132] ~() Fixnum
]
=> 0
